644674672 has 10 divisors (see below), whose sum is σ = 1249057208. Its totient is φ = 322337328.

The previous prime is 644674627. The next prime is 644674673. The reversal of 644674672 is 276476446.

644674672 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644674673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20146068 + ... + 20146099.

Almost surely, 2^644674672 is an apocalyptic number.

It is an amenable number.

644674672 is a deficient number, since it is larger than the sum of its proper divisors (604382536).

644674672 is a wasteful number, since it uses less digits than its factorization.

644674672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40292175 (or 40292169 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 46.

The square root of 644674672 is about 25390.4445018200. Note that the first 3 decimals coincide. The cubic root of 644674672 is about 863.8669705451.

It can be divided in two parts, 6446 and 74672, that added together give a palindrome (81118).

The spelling of 644674672 in words is "six hundred forty-four million, six hundred seventy-four thousand, six hundred seventy-two".