86815231 has 4 divisors (see below), whose sum is σ = 87124464. Its totient is φ = 86506000.

The previous prime is 86815229. The next prime is 86815259. The reversal of 86815231 is 13251868.

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

It is a cyclic number.

It is not a de Polignac number, because 86815231 - 2¹ = 86815229 is a prime.

It is a super-2 number, since 2×86815231² = 15073768667166722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86818231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 154195 + ... + 154756.

It is an arithmetic number, because the mean of its divisors is an integer number (21781116).

Almost surely, 2^86815231 is an apocalyptic number.

86815231 is a deficient number, since it is larger than the sum of its proper divisors (309233).

86815231 is a wasteful number, since it uses less digits than its factorization.

86815231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309232.

The product of its digits is 11520, while the sum is 34.

The square root of 86815231 is about 9317.4691306170. The cubic root of 86815231 is about 442.7908539252.

The spelling of 86815231 in words is "eighty-six million, eight hundred fifteen thousand, two hundred thirty-one".