644631284 has 24 divisors (see below), whose sum is σ = 1231507200. Its totient is φ = 292812480.

The previous prime is 644631277. The next prime is 644631289. The reversal of 644631284 is 482136446.

644631284 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×644631284² = 831098984622977312, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644631289) 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, 73232 + ... + 81560.

It is an arithmetic number, because the mean of its divisors is an integer number (51312800).

Almost surely, 2^644631284 is an apocalyptic number.

It is an amenable number.

644631284 is a deficient number, since it is larger than the sum of its proper divisors (586875916).

644631284 is a wasteful number, since it uses less digits than its factorization.

644631284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10103 (or 10101 counting only the distinct ones).

The product of its digits is 110592, while the sum is 38.

The square root of 644631284 is about 25389.5900715234. The cubic root of 644631284 is about 863.8475900717.

The spelling of 644631284 in words is "six hundred forty-four million, six hundred thirty-one thousand, two hundred eighty-four".