644127860620 has 12 divisors (see below), whose sum is σ = 1352668507344. Its totient is φ = 257651144240.

The previous prime is 644127860599. The next prime is 644127860641. The reversal of 644127860620 is 26068721446.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (644127860599) and next prime (644127860641).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16103196496 + ... + 16103196535.

It is an arithmetic number, because the mean of its divisors is an integer number (112722375612).

Almost surely, 2^644127860620 is an apocalyptic number.

It is an amenable number.

644127860620 is an abundant number, since it is smaller than the sum of its proper divisors (708540646724).

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

644127860620 is a wasteful number, since it uses less digits than its factorization.

644127860620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32206393040 (or 32206393038 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 46.

The spelling of 644127860620 in words is "six hundred forty-four billion, one hundred twenty-seven million, eight hundred sixty thousand, six hundred twenty".