231564217 has 8 divisors (see below), whose sum is σ = 239819400. Its totient is φ = 223327104.

The previous prime is 231564211. The next prime is 231564227. The reversal of 231564217 is 712465132.

It can be written as a sum of positive squares in 4 ways, for example, as 91757241 + 139806976 = 9579^2 + 11824^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 231564217 - 2²⁷ = 97346489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231564211) 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 7 ways as a sum of consecutive naturals, for example, 24909 + ... + 32917.

It is an arithmetic number, because the mean of its divisors is an integer number (29977425).

Almost surely, 2^231564217 is an apocalyptic number.

It is an amenable number.

231564217 is a deficient number, since it is larger than the sum of its proper divisors (8255183).

231564217 is an equidigital number, since it uses as much as digits as its factorization.

231564217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9035.

The product of its digits is 10080, while the sum is 31.

The square root of 231564217 is about 15217.2342099345. The cubic root of 231564217 is about 614.0783931214.

The spelling of 231564217 in words is "two hundred thirty-one million, five hundred sixty-four thousand, two hundred seventeen".