681994868 has 12 divisors (see below), whose sum is σ = 1197740292. Its totient is φ = 339783360.

The previous prime is 681994867. The next prime is 681994871. The reversal of 681994868 is 868499186.

It can be written as a sum of positive squares in 2 ways, for example, as 333500644 + 348494224 = 18262^2 + 18668^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681994867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 302255 + ... + 304502.

It is an arithmetic number, because the mean of its divisors is an integer number (99811691).

Almost surely, 2^681994868 is an apocalyptic number.

It is an amenable number.

681994868 is a deficient number, since it is larger than the sum of its proper divisors (515745424).

681994868 is a wasteful number, since it uses less digits than its factorization.

681994868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 607042 (or 607040 counting only the distinct ones).

The product of its digits is 5971968, while the sum is 59.

The square root of 681994868 is about 26115.0314569981. The cubic root of 681994868 is about 880.2250061688.

The spelling of 681994868 in words is "six hundred eighty-one million, nine hundred ninety-four thousand, eight hundred sixty-eight".