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31640625 = 3458
BaseRepresentation
bin111100010110…
…0110000110001
32012112111210000
41320230300301
531100000000
63050100213
7532640502
oct170546061
965474700
1031640625
1116951085
12a71a669
13672a983
1442b8ba9
152ba0000
hex1e2cc31

31640625 has 45 divisors (see below), whose sum is σ = 59082001. Its totient is φ = 16875000.

The previous prime is 31640611. The next prime is 31640659. The reversal of 31640625 is 52604613.

The square root of 31640625 is 5625.

It is a perfect power (a square, a biquadrate), and thus also a powerful number.

31640625 is a `hidden beast` number, since 31 + 6 + 4 + 0 + 625 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 22496049 + 9144576 = 4743^2 + 3024^2 .

It is a tau number, because it is divible by the number of its divisors (45).

It is not a de Polignac number, because 31640625 - 215 = 31607857 is a prime.

It is a super-2 number, since 2×316406252 = 2002258300781250, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a nialpdrome in base 5.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 6328123 + ... + 6328127.

Almost surely, 231640625 is an apocalyptic number.

31640625 is the 5625-th square number.

31640625 is the 2813-rd centered octagonal number.

It is an amenable number.

31640625 is a deficient number, since it is larger than the sum of its proper divisors (27441376).

31640625 is an frugal number, since it uses more digits than its factorization.

31640625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52 (or 8 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The cubic root of 31640625 is about 316.2872494882.

The spelling of 31640625 in words is "thirty-one million, six hundred forty thousand, six hundred twenty-five".

Divisors: 1 3 5 9 15 25 27 45 75 81 125 135 225 375 405 625 675 1125 1875 2025 3125 3375 5625 9375 10125 15625 16875 28125 46875 50625 78125 84375 140625 234375 253125 390625 421875 703125 1171875 1265625 2109375 3515625 6328125 10546875 31640625