681578694 has 12 divisors (see below), whose sum is σ = 1476753876. Its totient is φ = 227192892.

The previous prime is 681578693. The next prime is 681578701. The reversal of 681578694 is 496875186.

681578694 is a `hidden beast` number, since 6 + 8 + 1 + 578 + 69 + 4 = 666.

It is a super-2 number, since 2×681578694² = 929099032229491272, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 681578694.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681578693) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18932724 + ... + 18932759.

It is an arithmetic number, because the mean of its divisors is an integer number (123062823).

Almost surely, 2^681578694 is an apocalyptic number.

681578694 is an abundant number, since it is smaller than the sum of its proper divisors (795175182).

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

681578694 is a wasteful number, since it uses less digits than its factorization.

681578694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37865491 (or 37865488 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 54.

The square root of 681578694 is about 26107.0621480089. The cubic root of 681578694 is about 880.0459230511.

The spelling of 681578694 in words is "six hundred eighty-one million, five hundred seventy-eight thousand, six hundred ninety-four".