231312129 has 4 divisors (see below), whose sum is σ = 308416176. Its totient is φ = 154208084.

The previous prime is 231312121. The next prime is 231312139. The reversal of 231312129 is 921213132.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 231312129 - 2³ = 231312121 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 231312099 and 231312108.

It is not an unprimeable number, because it can be changed into a prime (231312121) 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, 38552019 + ... + 38552024.

It is an arithmetic number, because the mean of its divisors is an integer number (77104044).

Almost surely, 2^231312129 is an apocalyptic number.

It is an amenable number.

231312129 is a deficient number, since it is larger than the sum of its proper divisors (77104047).

231312129 is an equidigital number, since it uses as much as digits as its factorization.

231312129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77104046.

The product of its digits is 648, while the sum is 24.

The square root of 231312129 is about 15208.9489774935. The cubic root of 231312129 is about 613.8554772725.

The spelling of 231312129 in words is "two hundred thirty-one million, three hundred twelve thousand, one hundred twenty-nine".