644276232 has 48 divisors (see below), whose sum is σ = 1746274140. Its totient is φ = 214591488.

The previous prime is 644276203. The next prime is 644276233. The reversal of 644276232 is 232672446.

644276232 is a `hidden beast` number, since 6 + 4 + 4 + 27 + 623 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 590781636 + 53494596 = 24306^2 + 7314^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (644276233) 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 11 ways as a sum of consecutive naturals, for example, 119548 + ... + 124820.

Almost surely, 2^644276232 is an apocalyptic number.

It is an amenable number.

644276232 is an abundant number, since it is smaller than the sum of its proper divisors (1101997908).

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

644276232 is a wasteful number, since it uses less digits than its factorization.

644276232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6982 (or 6975 counting only the distinct ones).

The product of its digits is 96768, while the sum is 36.

The square root of 644276232 is about 25382.5970302489. The cubic root of 644276232 is about 863.6889634016.

The spelling of 644276232 in words is "six hundred forty-four million, two hundred seventy-six thousand, two hundred thirty-two".