644462076 has 12 divisors (see below), whose sum is σ = 1503744872. Its totient is φ = 214820688.

The previous prime is 644462051. The next prime is 644462089. The reversal of 644462076 is 670264446.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26852575 + ... + 26852598.

Almost surely, 2^644462076 is an apocalyptic number.

It is an amenable number.

644462076 is an abundant number, since it is smaller than the sum of its proper divisors (859282796).

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

644462076 is a wasteful number, since it uses less digits than its factorization.

644462076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53705180 (or 53705178 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 39.

The square root of 644462076 is about 25386.2576210043. The cubic root of 644462076 is about 863.7720002383.

The spelling of 644462076 in words is "six hundred forty-four million, four hundred sixty-two thousand, seventy-six".