664867156856 has 64 divisors (see below), whose sum is σ = 1444603372800. Its totient is φ = 280967470848.

The previous prime is 664867156831. The next prime is 664867156901. The reversal of 664867156856 is 658651768466.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17719091 + ... + 17756573.

It is an arithmetic number, because the mean of its divisors is an integer number (22571927700).

Almost surely, 2^664867156856 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 664867156856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (722301686400).

664867156856 is an abundant number, since it is smaller than the sum of its proper divisors (779736215944).

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

664867156856 is a wasteful number, since it uses less digits than its factorization.

664867156856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41908 (or 41904 counting only the distinct ones).

The product of its digits is 348364800, while the sum is 68.

The spelling of 664867156856 in words is "six hundred sixty-four billion, eight hundred sixty-seven million, one hundred fifty-six thousand, eight hundred fifty-six".