231139979 has 4 divisors (see below), whose sum is σ = 264159984. Its totient is φ = 198119976.

The previous prime is 231139957. The next prime is 231140023. The reversal of 231139979 is 979931132.

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 231139979 - 2²⁰ = 230091403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231139679) 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, 16509992 + ... + 16510005.

It is an arithmetic number, because the mean of its divisors is an integer number (66039996).

Almost surely, 2^231139979 is an apocalyptic number.

231139979 is a deficient number, since it is larger than the sum of its proper divisors (33020005).

231139979 is an equidigital number, since it uses as much as digits as its factorization.

231139979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33020004.

The product of its digits is 91854, while the sum is 44.

The square root of 231139979 is about 15203.2884271792. The cubic root of 231139979 is about 613.7031557501.

The spelling of 231139979 in words is "two hundred thirty-one million, one hundred thirty-nine thousand, nine hundred seventy-nine".