644974583480 has 64 divisors (see below), whose sum is σ = 1472955494400. Its totient is φ = 254147149440.

The previous prime is 644974583479. The next prime is 644974583489. The reversal of 644974583480 is 84385479446.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644974583489) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 377111 + ... + 1196729.

It is an arithmetic number, because the mean of its divisors is an integer number (23014929600).

Almost surely, 2^644974583480 is an apocalyptic number.

It is an amenable number.

644974583480 is an abundant number, since it is smaller than the sum of its proper divisors (827980910920).

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

644974583480 is a wasteful number, since it uses less digits than its factorization.

644974583480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 819924 (or 819920 counting only the distinct ones).

The product of its (nonzero) digits is 92897280, while the sum is 62.

The spelling of 644974583480 in words is "six hundred forty-four billion, nine hundred seventy-four million, five hundred eighty-three thousand, four hundred eighty".