231215865 has 16 divisors (see below), whose sum is σ = 370166208. Its totient is φ = 123241536.

The previous prime is 231215863. The next prime is 231215891. The reversal of 231215865 is 568512132.

231215865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 231215865 - 2¹ = 231215863 is a prime.

It is not an unprimeable number, because it can be changed into a prime (231215863) 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, 29547 + ... + 36543.

It is an arithmetic number, because the mean of its divisors is an integer number (23135388).

Almost surely, 2^231215865 is an apocalyptic number.

It is an amenable number.

231215865 is a deficient number, since it is larger than the sum of its proper divisors (138950343).

231215865 is a wasteful number, since it uses less digits than its factorization.

231215865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9208.

The product of its digits is 14400, while the sum is 33.

The square root of 231215865 is about 15205.7839324383. The cubic root of 231215865 is about 613.7703104128.

Adding to 231215865 its reverse (568512132), we get a palindrome (799727997).

The spelling of 231215865 in words is "two hundred thirty-one million, two hundred fifteen thousand, eight hundred sixty-five".