9000 (nine thousand) is the natural number following 8999 and preceding 9001.
Selected numbers in the range 9001–9999
9001 to 9099 9001 – sexy prime with 9007 9007 – sexy prime with 9001 9009 – centered cube number 9025 = 952, centered octagonal number 9029 – Sophie Germain prime 9041 – super-prime 9045 – triangular number 9059 – Sophie Germain prime 9072 – decagonal number 9077 – Markov number 9091 – unique prime
9100 to 9199 9103 – super-prime 9126 – pentagonal pyramidal number 9139 – tetrahedral number 9175 – smallest (provable) generalized Sierpiński number in base 10: is always divisible by one of the prime numbers }. 9180 – triangular number
9200 to 9299 9221 – Sophie Germain prime 9224 – octahedral number 9232 – Peak of 27 in Collatz Conjecture. 9241 – cuban prime of the form x = y + 1 9261 = 213, largest 4 digit perfect cube 9272 – weird number 9283 – centered heptagonal number 9293 – Sophie Germain prime, super-prime
9300 to 9399 9316 – triangular number 9319 – super-prime 9334 – nonagonal number 9349 – Lucas prime, Fibonacci number 9361 – star number 9371 – Sophie Germain prime 9376 – 1-automorphic number 9397 – balanced prime
9400 to 9499 9403 – super-prime 9409 = 972, centered octagonal number 9419 – Sophie Germain prime 9439 – completes the twelfth prime quadruplet set 9453 – triangular number 9455 – square pyramidal number 9457 – decagonal number 9461 – super-prime, twin prime 9467 – safe prime 9473 – Sophie Germain prime, balanced prime, Proth prime 9474 – Narcissistic number in base 10 9479 – Sophie Germain prime 9496 – Telephone/involution number
9500 to 9599 9539 – Sophie Germain prime, super-prime 9551 – first prime followed by as many as 35 consecutive composite numbers 9587 – safe prime, follows 35 consecutive composite numbers 9591 – triangular number 9592 – the number of primes under 100,000
9600 to 9699 9601 – Proth prime 9619 – super-prime 9629 – Sophie Germain prime 9647 – centered heptagonal number 9661 – super-prime, sum of nine consecutive primes (1049 + 1051 + 1061 + 1063 + 1069 + 1087 + 1091 + 1093 + 1097) 9689 – Sophie Germain prime 9699 – nonagonal number
9700 to 9799 9730 – triangular number 9739 – super-prime 9743 – safe prime 9791 – Sophie Germain prime
9800 to 9899 9800 – member of a Ruth-Aaron pair (first definition) with 9801 9801 = 992, the largest 4 digit perfect square, centered octagonal number, square pentagonal number, member of a Ruth-Aaron pair (first definition) with 9800 9833 – super-prime 9839 – safe prime 9841 – star number 9850 – decagonal number 9855 – magic constant for a 27×27 magic square, probably of numerological significance in Ancient Greece 9857 – Proth prime 9859 – super-prime 9870 – triangular number 9871 – balanced prime 9880 – tetrahedral number 9887 – safe prime
9900 to 9999 9901 – unique prime, sum of seven consecutive primes (1381 + 1399 + 1409 + 1423 + 1427 + 1429 + 1433) 9905 – number of compositions of 16 whose run-lengths are either weakly increasing or weakly decreasing 9923 – super-prime, probably smallest certainly executable prime number on x86 MS-DOS 9949 – sum of nine consecutive primes (1087 + 1091 + 1093 + 1097 + 1103 + 1109 + 1117 + 1123 + 1129) 9973 – super-prime; largest four-digit prime 9988 – number of prime knots with 13 crossings 9999 – Kaprekar number, repdigit
Prime numbers There are 112 prime numbers between 9000 and 10000: 9001, 9007, 9011, 9013, 9029, 9041, 9043, 9049, 9059, 9067, 9091, 9103, 9109, 9127, 9133, 9137, 9151, 9157, 9161, 9173, 9181, 9187, 9199, 9203, 9209, 9221, 9227, 9239, 9241, 9257, 9277, 9281, 9283, 9293, 9311, 9319, 9323, 9337, 9341, 9343, 9349, 9371, 9377, 9391, 9397, 9403, 9413, 9419, 9421, 9431, 9433, 9437, 9439, 9461, 9463, 9467, 9473, 9479, 9491, 9497, 9511, 9521, 9533, 9539, 9547, 9551, 9587, 9601, 9613, 9619, 9623, 9629, 9631, 9643, 9649, 9661, 9677, 9679, 9689, 9697, 9719, 9721, 9733, 9739, 9743, 9749, 9767, 9769, 9781, 9787, 9791, 9803, 9811, 9817, 9829, 9833, 9839, 9851, 9857, 9859, 9871, 9883, 9887, 9901, 9907, 9923, 9929, 9931, 9941, 9949, 9967, 9973
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