64640631312531 has 24 divisors (see below), whose sum is σ = 96591286406160. Its totient is φ = 41606971224000.

The previous prime is 64640631312529. The next prime is 64640631312557. The reversal of 64640631312531 is 13521313604646.

64640631312531 is a `hidden beast` number, since 6 + 4 + 6 + 4 + 0 + 631 + 3 + 1 + 2 + 5 + 3 + 1 = 666.

It is not a de Polignac number, because 64640631312531 - 2¹ = 64640631312529 is a prime.

It is a super-2 number, since 2×64640631312531² (a number of 28 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (64640631312581) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11548681 + ... + 16206581.

It is an arithmetic number, because the mean of its divisors is an integer number (4024636933590).

Almost surely, 2^{64640631312531} is an apocalyptic number.

64640631312531 is a deficient number, since it is larger than the sum of its proper divisors (31950655093629).

64640631312531 is a wasteful number, since it uses less digits than its factorization.

64640631312531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4711107 (or 4711104 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 45.

The spelling of 64640631312531 in words is "sixty-four trillion, six hundred forty billion, six hundred thirty-one million, three hundred twelve thousand, five hundred thirty-one".