644550465250 has 32 divisors (see below), whose sum is σ = 1277574860016. Its totient is φ = 242654291200.

The previous prime is 644550465241. The next prime is 644550465311. The reversal of 644550465250 is 52564055446.

It can be written as a sum of positive squares in 8 ways, for example, as 5329 + 644550459921 = 73^2 + 802839^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 644550465250.

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, 75825217 + ... + 75833716.

Almost surely, 2^644550465250 is an apocalyptic number.

644550465250 is a deficient number, since it is larger than the sum of its proper divisors (633024394766).

644550465250 is a wasteful number, since it uses less digits than its factorization.

644550465250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151658967 (or 151658957 counting only the distinct ones).

The product of its (nonzero) digits is 2880000, while the sum is 46.

The spelling of 644550465250 in words is "six hundred forty-four billion, five hundred fifty million, four hundred sixty-five thousand, two hundred fifty".