861938631 has 32 divisors (see below), whose sum is σ = 1289882880. Its totient is φ = 568840608.

The previous prime is 861938617. The next prime is 861938633. The reversal of 861938631 is 136839168.

It is a happy number.

861938631 is a `hidden beast` number, since 8 + 6 + 1 + 9 + 3 + 8 + 631 = 666.

It is not a de Polignac number, because 861938631 - 2¹⁴ = 861922247 is a prime.

It is a super-2 number, since 2×861938631² = 1485876407220308322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861938633) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1845460 + ... + 1845926.

It is an arithmetic number, because the mean of its divisors is an integer number (40308840).

Almost surely, 2^861938631 is an apocalyptic number.

861938631 is a deficient number, since it is larger than the sum of its proper divisors (427944249).

861938631 is a wasteful number, since it uses less digits than its factorization.

861938631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1020 (or 1014 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 861938631 is about 29358.7913749868. The cubic root of 861938631 is about 951.6825698132.

The spelling of 861938631 in words is "eight hundred sixty-one million, nine hundred thirty-eight thousand, six hundred thirty-one".