681185631 has 16 divisors (see below), whose sum is σ = 1099056384. Its totient is φ = 366351744.

The previous prime is 681185629. The next prime is 681185657. The reversal of 681185631 is 136581186.

It is not a de Polignac number, because 681185631 - 2¹ = 681185629 is a prime.

It is a super-2 number, since 2×681185631² = 928027727761736322, 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 681185631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681183631) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 953685 + ... + 954398.

It is an arithmetic number, because the mean of its divisors is an integer number (68691024).

Almost surely, 2^681185631 is an apocalyptic number.

681185631 is a deficient number, since it is larger than the sum of its proper divisors (417870753).

681185631 is a wasteful number, since it uses less digits than its factorization.

681185631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1908110.

The product of its digits is 34560, while the sum is 39.

The square root of 681185631 is about 26099.5331567444. The cubic root of 681185631 is about 879.8767178365.

The spelling of 681185631 in words is "six hundred eighty-one million, one hundred eighty-five thousand, six hundred thirty-one".