861892131 has 4 divisors (see below), whose sum is σ = 1149189512. Its totient is φ = 574594752.

The previous prime is 861892127. The next prime is 861892153. The reversal of 861892131 is 131298168.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 861892131 - 2² = 861892127 is a prime.

It is a super-2 number, since 2×861892131² = 1485716090959442322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 861892131.

It is not an unprimeable number, because it can be changed into a prime (861892121) 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, 143648686 + ... + 143648691.

It is an arithmetic number, because the mean of its divisors is an integer number (287297378).

Almost surely, 2^861892131 is an apocalyptic number.

861892131 is a deficient number, since it is larger than the sum of its proper divisors (287297381).

861892131 is a wasteful number, since it uses less digits than its factorization.

861892131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287297380.

The product of its digits is 20736, while the sum is 39.

The square root of 861892131 is about 29357.9994379726. Note that the first 3 decimals coincide. The cubic root of 861892131 is about 951.6654556654.

The spelling of 861892131 in words is "eight hundred sixty-one million, eight hundred ninety-two thousand, one hundred thirty-one".