864215231 has 4 divisors (see below), whose sum is σ = 942780264. Its totient is φ = 785650200.

The previous prime is 864215221. The next prime is 864215239. The reversal of 864215231 is 132512468.

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 864215231 - 2¹⁴ = 864198847 is a prime.

It is a super-2 number, since 2×864215231² = 1493735930984766722, 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 (864215239) 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, 39282500 + ... + 39282521.

It is an arithmetic number, because the mean of its divisors is an integer number (235695066).

Almost surely, 2^864215231 is an apocalyptic number.

864215231 is a deficient number, since it is larger than the sum of its proper divisors (78565033).

864215231 is a wasteful number, since it uses less digits than its factorization.

864215231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78565032.

The product of its digits is 11520, while the sum is 32.

The square root of 864215231 is about 29397.5378390776. The cubic root of 864215231 is about 952.5197120952.

Adding to 864215231 its reverse (132512468), we get a palindrome (996727699).

The spelling of 864215231 in words is "eight hundred sixty-four million, two hundred fifteen thousand, two hundred thirty-one".