645029931 has 16 divisors (see below), whose sum is σ = 1058511104. Its totient is φ = 340235424.

The previous prime is 645029923. The next prime is 645030007. The reversal of 645029931 is 139920546.

It is not a de Polignac number, because 645029931 - 2³ = 645029923 is a prime.

It is a super-2 number, since 2×645029931² = 832127223771729522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 645029931.

It is not an unprimeable number, because it can be changed into a prime (645029911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1181101 + ... + 1181646.

It is an arithmetic number, because the mean of its divisors is an integer number (66156944).

Almost surely, 2^645029931 is an apocalyptic number.

645029931 is a deficient number, since it is larger than the sum of its proper divisors (413481173).

645029931 is a wasteful number, since it uses less digits than its factorization.

645029931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2362770.

The product of its (nonzero) digits is 58320, while the sum is 39.

The square root of 645029931 is about 25397.4394575516. The cubic root of 645029931 is about 864.0256242936.

The spelling of 645029931 in words is "six hundred forty-five million, twenty-nine thousand, nine hundred thirty-one".