644485476 has 24 divisors (see below), whose sum is σ = 1522837120. Its totient is φ = 212108832.

The previous prime is 644485451. The next prime is 644485483. The reversal of 644485476 is 674584446.

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, 338971 + ... + 340866.

Almost surely, 2^644485476 is an apocalyptic number.

It is an amenable number.

644485476 is an abundant number, since it is smaller than the sum of its proper divisors (878351644).

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

644485476 is a wasteful number, since it uses less digits than its factorization.

644485476 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679923 (or 679921 counting only the distinct ones).

The product of its digits is 2580480, while the sum is 48.

The square root of 644485476 is about 25386.7184960956. The cubic root of 644485476 is about 863.7824544454.

The spelling of 644485476 in words is "six hundred forty-four million, four hundred eighty-five thousand, four hundred seventy-six".