644523004 has 6 divisors (see below), whose sum is σ = 1127915264. Its totient is φ = 322261500.

The previous prime is 644522981. The next prime is 644523029. The reversal of 644523004 is 400325446.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80565372 + ... + 80565379.

Almost surely, 2^644523004 is an apocalyptic number.

It is an amenable number.

644523004 is a deficient number, since it is larger than the sum of its proper divisors (483392260).

644523004 is a wasteful number, since it uses less digits than its factorization.

644523004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161130755 (or 161130753 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 28.

The square root of 644523004 is about 25387.4576119784. The cubic root of 644523004 is about 863.7992199636.

The spelling of 644523004 in words is "six hundred forty-four million, five hundred twenty-three thousand, four".