644199716 has 24 divisors (see below), whose sum is σ = 1165226496. Its totient is φ = 311304960.

The previous prime is 644199713. The next prime is 644199763. The reversal of 644199716 is 617991446.

It is not an unprimeable number, because it can be changed into a prime (644199713) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107060 + ... + 112916.

It is an arithmetic number, because the mean of its divisors is an integer number (48551104).

Almost surely, 2^644199716 is an apocalyptic number.

It is an amenable number.

644199716 is a deficient number, since it is larger than the sum of its proper divisors (521026780).

644199716 is a wasteful number, since it uses less digits than its factorization.

644199716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6779 (or 6777 counting only the distinct ones).

The product of its digits is 326592, while the sum is 47.

The square root of 644199716 is about 25381.0897323184. The cubic root of 644199716 is about 863.6547706967.

The spelling of 644199716 in words is "six hundred forty-four million, one hundred ninety-nine thousand, seven hundred sixteen".