231520129 has 2 divisors, whose sum is σ = 231520130. Its totient is φ = 231520128.

The previous prime is 231520097. The next prime is 231520171. The reversal of 231520129 is 921025132.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 191767104 + 39753025 = 13848^2 + 6305^2 .

It is a cyclic number.

It is not a de Polignac number, because 231520129 - 2⁵ = 231520097 is a prime.

It is not a weakly prime, because it can be changed into another prime (231520199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115760064 + 115760065.

It is an arithmetic number, because the mean of its divisors is an integer number (115760065).

Almost surely, 2^231520129 is an apocalyptic number.

It is an amenable number.

231520129 is a deficient number, since it is larger than the sum of its proper divisors (1).

231520129 is an equidigital number, since it uses as much as digits as its factorization.

231520129 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 231520129 is about 15215.7855203075. The cubic root of 231520129 is about 614.0394187540.

The spelling of 231520129 in words is "two hundred thirty-one million, five hundred twenty thousand, one hundred twenty-nine".