644277032 has 32 divisors (see below), whose sum is σ = 1381536000. Its totient is φ = 275930304.

The previous prime is 644276981. The next prime is 644277037. The reversal of 644277032 is 230772446.

It is a junction number, because it is equal to n+sod(n) for n = 644276983 and 644277001.

It is not an unprimeable number, because it can be changed into a prime (644277037) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106193 + ... + 112095.

It is an arithmetic number, because the mean of its divisors is an integer number (43173000).

Almost surely, 2^644277032 is an apocalyptic number.

It is an amenable number.

644277032 is an abundant number, since it is smaller than the sum of its proper divisors (737258968).

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

644277032 is a wasteful number, since it uses less digits than its factorization.

644277032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7865 (or 7861 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 35.

The square root of 644277032 is about 25382.6127890728. The cubic root of 644277032 is about 863.6893208833.

The spelling of 644277032 in words is "six hundred forty-four million, two hundred seventy-seven thousand, thirty-two".