644915560260 has 24 divisors (see below), whose sum is σ = 1805763568896. Its totient is φ = 171977482720.

The previous prime is 644915560243. The next prime is 644915560283. The reversal of 644915560260 is 62065519446.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5374296276 + ... + 5374296395.

It is an arithmetic number, because the mean of its divisors is an integer number (75240148704).

Almost surely, 2^644915560260 is an apocalyptic number.

644915560260 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

644915560260 is an abundant number, since it is smaller than the sum of its proper divisors (1160848008636).

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

644915560260 is a wasteful number, since it uses less digits than its factorization.

644915560260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10748592683 (or 10748592681 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 48.

The spelling of 644915560260 in words is "six hundred forty-four billion, nine hundred fifteen million, five hundred sixty thousand, two hundred sixty".