664612567256 has 128 divisors (see below), whose sum is σ = 1427065516800. Its totient is φ = 287509248000.

The previous prime is 664612567243. The next prime is 664612567261. The reversal of 664612567256 is 652765216466.

It is a super-2 number, since 2×664612567256² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27874316 + ... + 27898148.

It is an arithmetic number, because the mean of its divisors is an integer number (11148949350).

Almost surely, 2^664612567256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664612567256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (713532758400).

664612567256 is an abundant number, since it is smaller than the sum of its proper divisors (762452949544).

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

664612567256 is a wasteful number, since it uses less digits than its factorization.

664612567256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24081 (or 24077 counting only the distinct ones).

The product of its digits is 21772800, while the sum is 56.

The spelling of 664612567256 in words is "six hundred sixty-four billion, six hundred twelve million, five hundred sixty-seven thousand, two hundred fifty-six".