644402674 has 16 divisors (see below), whose sum is σ = 983102400. Its totient is φ = 316728720.

The previous prime is 644402623. The next prime is 644402713. The reversal of 644402674 is 476204446.

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, 43057 + ... + 56059.

It is an arithmetic number, because the mean of its divisors is an integer number (61443900).

Almost surely, 2^644402674 is an apocalyptic number.

644402674 is a deficient number, since it is larger than the sum of its proper divisors (338699726).

644402674 is a wasteful number, since it uses less digits than its factorization.

644402674 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13425.

The product of its (nonzero) digits is 129024, while the sum is 37.

The square root of 644402674 is about 25385.0876303392. The cubic root of 644402674 is about 863.7454606053.

The spelling of 644402674 in words is "six hundred forty-four million, four hundred two thousand, six hundred seventy-four".