644065116 has 48 divisors (see below), whose sum is σ = 1611792000. Its totient is φ = 199547712.

The previous prime is 644065109. The next prime is 644065127. The reversal of 644065116 is 611560446.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14566 + ... + 38733.

It is an arithmetic number, because the mean of its divisors is an integer number (33579000).

Almost surely, 2^644065116 is an apocalyptic number.

It is an amenable number.

644065116 is an abundant number, since it is smaller than the sum of its proper divisors (967726884).

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

644065116 is a wasteful number, since it uses less digits than its factorization.

644065116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53378 (or 53376 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 644065116 is about 25378.4380134003. The cubic root of 644065116 is about 863.5946154237.

The spelling of 644065116 in words is "six hundred forty-four million, sixty-five thousand, one hundred sixteen".