231164561 has 4 divisors (see below), whose sum is σ = 232064292. Its totient is φ = 230264832.

The previous prime is 231164509. The next prime is 231164579. The reversal of 231164561 is 165461132.

It is a happy number.

231164561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 197233936 + 33930625 = 14044^2 + 5825^2 .

It is a cyclic number.

It is not a de Polignac number, because 231164561 - 2⁶ = 231164497 is a prime.

It is a super-5 number, since 5×231164561⁵ (a number of 43 digits) contains 55555 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231164581) 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, 449480 + ... + 449993.

It is an arithmetic number, because the mean of its divisors is an integer number (58016073).

Almost surely, 2^231164561 is an apocalyptic number.

It is an amenable number.

231164561 is a deficient number, since it is larger than the sum of its proper divisors (899731).

231164561 is an equidigital number, since it uses as much as digits as its factorization.

231164561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 899730.

The product of its digits is 4320, while the sum is 29.

The square root of 231164561 is about 15204.0968492048. The cubic root of 231164561 is about 613.7249109888.

The spelling of 231164561 in words is "two hundred thirty-one million, one hundred sixty-four thousand, five hundred sixty-one".