681397626 has 64 divisors (see below), whose sum is σ = 1711584000. Its totient is φ = 179702208.

The previous prime is 681397603. The next prime is 681397643. The reversal of 681397626 is 626793186.

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, 14020 + ... + 39488.

It is an arithmetic number, because the mean of its divisors is an integer number (26743500).

Almost surely, 2^681397626 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681397626, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (855792000).

681397626 is an abundant number, since it is smaller than the sum of its proper divisors (1030186374).

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

681397626 is a wasteful number, since it uses less digits than its factorization.

681397626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25508 (or 25494 counting only the distinct ones).

The product of its digits is 653184, while the sum is 48.

The square root of 681397626 is about 26103.5941203506. The cubic root of 681397626 is about 879.9679852334.

The spelling of 681397626 in words is "six hundred eighty-one million, three hundred ninety-seven thousand, six hundred twenty-six".