644970372 has 24 divisors (see below), whose sum is σ = 1506021216. Its totient is φ = 214834368.

The previous prime is 644970367. The next prime is 644970413. The reversal of 644970372 is 273079446.

644970372 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 1558 + ... + 35949.

It is an arithmetic number, because the mean of its divisors is an integer number (62750884).

Almost surely, 2^644970372 is an apocalyptic number.

It is an amenable number.

644970372 is an abundant number, since it is smaller than the sum of its proper divisors (861050844).

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

644970372 is a wasteful number, since it uses less digits than its factorization.

644970372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38947 (or 38945 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 42.

The square root of 644970372 is about 25396.2668910216. The cubic root of 644970372 is about 863.9990301344. Note that the first 3 decimals are identical.

The spelling of 644970372 in words is "six hundred forty-four million, nine hundred seventy thousand, three hundred seventy-two".