644357552 has 20 divisors (see below), whose sum is σ = 1263486840. Its totient is φ = 318296448.

The previous prime is 644357543. The next prime is 644357617. The reversal of 644357552 is 255753446.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 241277 + ... + 243932.

It is an arithmetic number, because the mean of its divisors is an integer number (63174342).

Almost surely, 2^644357552 is an apocalyptic number.

It is an amenable number.

644357552 is a deficient number, since it is larger than the sum of its proper divisors (619129288).

644357552 is a wasteful number, since it uses less digits than its factorization.

644357552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 485300 (or 485294 counting only the distinct ones).

The product of its digits is 504000, while the sum is 41.

The square root of 644357552 is about 25384.1988646481. The cubic root of 644357552 is about 863.7252999025.

The spelling of 644357552 in words is "six hundred forty-four million, three hundred fifty-seven thousand, five hundred fifty-two".