645641031 has 16 divisors (see below), whose sum is σ = 985055744. Its totient is φ = 368479584.

The previous prime is 645640921. The next prime is 645641041. The reversal of 645641031 is 130146546.

It is not a de Polignac number, because 645641031 - 2⁹ = 645640519 is a prime.

It is a super-2 number, since 2×645641031² = 833704681821485922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 645641031.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645641041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1396 + ... + 35961.

It is an arithmetic number, because the mean of its divisors is an integer number (61565984).

Almost surely, 2^645641031 is an apocalyptic number.

645641031 is a deficient number, since it is larger than the sum of its proper divisors (339414713).

645641031 is a wasteful number, since it uses less digits than its factorization.

645641031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38190.

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 645641031 is about 25409.4673497891. The cubic root of 645641031 is about 864.2983968568.

Adding to 645641031 its reverse (130146546), we get a palindrome (775787577).

The spelling of 645641031 in words is "six hundred forty-five million, six hundred forty-one thousand, thirty-one".