681679881 has 21 divisors (see below), whose sum is σ = 1023110301. Its totient is φ = 453983292.

The previous prime is 681679879. The next prime is 681679931. The reversal of 681679881 is 188976186.

The square root of 681679881 is 26109.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 681679881 - 2¹ = 681679879 is a prime.

It is a super-2 number, since 2×681679881² = 929374920320348322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (681679841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 704460 + ... + 705426.

Almost surely, 2^681679881 is an apocalyptic number.

681679881 is the 26109-th square number.

681679881 is the 13055-th centered octagonal number.

It is an amenable number.

681679881 is a deficient number, since it is larger than the sum of its proper divisors (341430420).

681679881 is an frugal number, since it uses more digits than its factorization.

681679881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1952 (or 970 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 54.

The cubic root of 681679881 is about 880.0894713609.

The spelling of 681679881 in words is "six hundred eighty-one million, six hundred seventy-nine thousand, eight hundred eighty-one".