644530626963 has 24 divisors (see below), whose sum is σ = 984305275200. Its totient is φ = 405278681904.

The previous prime is 644530626917. The next prime is 644530626967. The reversal of 644530626963 is 369626035446.

644530626963 is a `hidden beast` number, since 6 + 4 + 4 + 5 + 3 + 0 + 626 + 9 + 6 + 3 = 666.

It is not a de Polignac number, because 644530626963 - 2²⁴ = 644513849747 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644530626967) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8263353 + ... + 8340986.

It is an arithmetic number, because the mean of its divisors is an integer number (41012719800).

Almost surely, 2^644530626963 is an apocalyptic number.

644530626963 is a deficient number, since it is larger than the sum of its proper divisors (339774648237).

644530626963 is a wasteful number, since it uses less digits than its factorization.

644530626963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16604591 (or 16604588 counting only the distinct ones).

The product of its (nonzero) digits is 16796160, while the sum is 54.

The spelling of 644530626963 in words is "six hundred forty-four billion, five hundred thirty million, six hundred twenty-six thousand, nine hundred sixty-three".