644374027710 has 256 divisors, whose sum is σ = 2021775206400. Its totient is φ = 144787098240.

The previous prime is 644374027697. The next prime is 644374027751. The reversal of 644374027710 is 17720473446.

644374027710 is a `hidden beast` number, since 6 + 4 + 4 + 374 + 0 + 277 + 1 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 8996640 + ... + 9067980.

It is an arithmetic number, because the mean of its divisors is an integer number (7897559400).

Almost surely, 2^644374027710 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644374027710, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1010887603200).

644374027710 is an abundant number, since it is smaller than the sum of its proper divisors (1377401178690).

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

644374027710 is an equidigital number, since it uses as much as digits as its factorization.

644374027710 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71435 (or 71417 counting only the distinct ones).

The product of its (nonzero) digits is 790272, while the sum is 45.

The spelling of 644374027710 in words is "six hundred forty-four billion, three hundred seventy-four million, twenty-seven thousand, seven hundred ten".