644594616 has 48 divisors (see below), whose sum is σ = 1756263600. Its totient is φ = 213574272.

The previous prime is 644594609. The next prime is 644594617. The reversal of 644594616 is 616495446.

It is a happy number.

644594616 is a `hidden beast` number, since 6 + 44 + 594 + 6 + 16 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644594617) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14781 + ... + 38828.

It is an arithmetic number, because the mean of its divisors is an integer number (36588825).

Almost surely, 2^644594616 is an apocalyptic number.

It is an amenable number.

644594616 is an abundant number, since it is smaller than the sum of its proper divisors (1111668984).

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

644594616 is a wasteful number, since it uses less digits than its factorization.

644594616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53788 (or 53781 counting only the distinct ones).

The product of its digits is 622080, while the sum is 45.

The square root of 644594616 is about 25388.8679542826. The cubic root of 644594616 is about 863.8312105977.

The spelling of 644594616 in words is "six hundred forty-four million, five hundred ninety-four thousand, six hundred sixteen".