646641931 has 16 divisors (see below), whose sum is σ = 705752320. Its totient is φ = 588915360.

The previous prime is 646641901. The next prime is 646641959. The reversal of 646641931 is 139146646.

646641931 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 646641931 - 2⁵ = 646641899 is a prime.

It is a super-2 number, since 2×646641931² = 836291573854817522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (646641901) 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, 442480 + ... + 443938.

It is an arithmetic number, because the mean of its divisors is an integer number (44109520).

Almost surely, 2^646641931 is an apocalyptic number.

646641931 is a deficient number, since it is larger than the sum of its proper divisors (59110389).

646641931 is a wasteful number, since it uses less digits than its factorization.

646641931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1906.

The product of its digits is 93312, while the sum is 40.

The square root of 646641931 is about 25429.1551373615. The cubic root of 646641931 is about 864.7447902253.

The spelling of 646641931 in words is "six hundred forty-six million, six hundred forty-one thousand, nine hundred thirty-one".