644298744 has 32 divisors (see below), whose sum is σ = 1618935120. Its totient is φ = 213674496.

The previous prime is 644298737. The next prime is 644298769. The reversal of 644298744 is 447892446.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 644298693 and 644298702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63409 + ... + 72864.

Almost surely, 2^644298744 is an apocalyptic number.

It is an amenable number.

644298744 is an abundant number, since it is smaller than the sum of its proper divisors (974636376).

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

644298744 is a wasteful number, since it uses less digits than its factorization.

644298744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136479 (or 136475 counting only the distinct ones).

The product of its digits is 1548288, while the sum is 48.

The square root of 644298744 is about 25383.0404798164. The cubic root of 644298744 is about 863.6990228236.

The spelling of 644298744 in words is "six hundred forty-four million, two hundred ninety-eight thousand, seven hundred forty-four".