681939594688 has 56 divisors (see below), whose sum is σ = 1477463105520. Its totient is φ = 309716613120.

The previous prime is 681939594683. The next prime is 681939594697. The reversal of 681939594688 is 886495939186.

It is a super-2 number, since 2×681939594688² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681939594683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 454668 + ... + 1253236.

Almost surely, 2^681939594688 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 681939594688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (738731552760).

681939594688 is an abundant number, since it is smaller than the sum of its proper divisors (795523510832).

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

681939594688 is a wasteful number, since it uses less digits than its factorization.

681939594688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799805 (or 799795 counting only the distinct ones).

The product of its digits is 806215680, while the sum is 76.

The spelling of 681939594688 in words is "six hundred eighty-one billion, nine hundred thirty-nine million, five hundred ninety-four thousand, six hundred eighty-eight".