644090532 has 24 divisors (see below), whose sum is σ = 1503600672. Its totient is φ = 214593600.

The previous prime is 644090527. The next prime is 644090537. The reversal of 644090532 is 235090446.

It is an interprime number because it is at equal distance from previous prime (644090527) and next prime (644090537).

It is a super-2 number, since 2×644090532² = 829705226824086048, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 644090493 and 644090502.

It is not an unprimeable number, because it can be changed into a prime (644090537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15607 + ... + 39137.

It is an arithmetic number, because the mean of its divisors is an integer number (62650028).

Almost surely, 2^644090532 is an apocalyptic number.

It is an amenable number.

644090532 is an abundant number, since it is smaller than the sum of its proper divisors (859510140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644090532 is a wasteful number, since it uses less digits than its factorization.

644090532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25819 (or 25817 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 33.

The square root of 644090532 is about 25378.9387484977. The cubic root of 644090532 is about 863.6059749542.

The spelling of 644090532 in words is "six hundred forty-four million, ninety thousand, five hundred thirty-two".