645046931531 has 8 divisors (see below), whose sum is σ = 672160662720. Its totient is φ = 618257915968.

The previous prime is 645046931471. The next prime is 645046931563. The reversal of 645046931531 is 135139640546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645046931531 is a prime.

It is a super-2 number, since 2×645046931531² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645046931591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81174851 + ... + 81182796.

It is an arithmetic number, because the mean of its divisors is an integer number (84020082840).

Almost surely, 2^645046931531 is an apocalyptic number.

645046931531 is a deficient number, since it is larger than the sum of its proper divisors (27113731189).

645046931531 is a wasteful number, since it uses less digits than its factorization.

645046931531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162357813.

The product of its (nonzero) digits is 1166400, while the sum is 47.

The spelling of 645046931531 in words is "six hundred forty-five billion, forty-six million, nine hundred thirty-one thousand, five hundred thirty-one".