644673004 has 6 divisors (see below), whose sum is σ = 1128177764. Its totient is φ = 322336500.

The previous prime is 644672969. The next prime is 644673019. The reversal of 644673004 is 400376446.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80584122 + ... + 80584129.

Almost surely, 2^644673004 is an apocalyptic number.

It is an amenable number.

644673004 is a deficient number, since it is larger than the sum of its proper divisors (483504760).

644673004 is a wasteful number, since it uses less digits than its factorization.

644673004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161168255 (or 161168253 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 34.

The square root of 644673004 is about 25390.4116547960. The cubic root of 644673004 is about 863.8662255020.

The spelling of 644673004 in words is "six hundred forty-four million, six hundred seventy-three thousand, four".