644568704514 has 128 divisors (see below), whose sum is σ = 1667503987200. Its totient is φ = 180744099840.

The previous prime is 644568704503. The next prime is 644568704551. The reversal of 644568704514 is 415407865446.

644568704514 is a `hidden beast` number, since 6 + 4 + 4 + 56 + 8 + 70 + 4 + 514 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 10506922 + ... + 10568090.

It is an arithmetic number, because the mean of its divisors is an integer number (13027374900).

Almost surely, 2^644568704514 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644568704514, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (833751993600).

644568704514 is an abundant number, since it is smaller than the sum of its proper divisors (1022935282686).

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

644568704514 is a wasteful number, since it uses less digits than its factorization.

644568704514 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61705 (or 61699 counting only the distinct ones).

The product of its (nonzero) digits is 12902400, while the sum is 54.

The spelling of 644568704514 in words is "six hundred forty-four billion, five hundred sixty-eight million, seven hundred four thousand, five hundred fourteen".