644530265203 has 32 divisors (see below), whose sum is σ = 742239590400. Its totient is φ = 553518489600.

The previous prime is 644530265179. The next prime is 644530265209. The reversal of 644530265203 is 302562035446.

It is a cyclic number.

It is not a de Polignac number, because 644530265203 - 2²⁵ = 644496710771 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644530265209) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 117805758 + ... + 117811228.

It is an arithmetic number, because the mean of its divisors is an integer number (23194987200).

Almost surely, 2^644530265203 is an apocalyptic number.

644530265203 is a deficient number, since it is larger than the sum of its proper divisors (97709325197).

644530265203 is a wasteful number, since it uses less digits than its factorization.

644530265203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7003.

The product of its (nonzero) digits is 518400, while the sum is 40.

The spelling of 644530265203 in words is "six hundred forty-four billion, five hundred thirty million, two hundred sixty-five thousand, two hundred three".