681336656 has 160 divisors (see below), whose sum is σ = 1866547200. Its totient is φ = 232035840.

The previous prime is 681336619. The next prime is 681336679. The reversal of 681336656 is 656633186.

It is a Harshad number since it is a multiple of its sum of digits (44).

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, 303185 + ... + 305423.

It is an arithmetic number, because the mean of its divisors is an integer number (11665920).

Almost surely, 2^681336656 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 681336656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (933273600).

681336656 is an abundant number, since it is smaller than the sum of its proper divisors (1185210544).

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

681336656 is a wasteful number, since it uses less digits than its factorization.

681336656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2297 (or 2291 counting only the distinct ones).

The product of its digits is 466560, while the sum is 44.

The square root of 681336656 is about 26102.4262473817. The cubic root of 681336656 is about 879.9417385671.

The spelling of 681336656 in words is "six hundred eighty-one million, three hundred thirty-six thousand, six hundred fifty-six".