31399129 has 2 divisors, whose sum is σ = 31399130. Its totient is φ = 31399128.

The previous prime is 31399097. The next prime is 31399157. The reversal of 31399129 is 92199313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26214400 + 5184729 = 5120^2 + 2277^2 .

It is a cyclic number.

It is not a de Polignac number, because 31399129 - 2⁵ = 31399097 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31399169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15699564 + 15699565.

It is an arithmetic number, because the mean of its divisors is an integer number (15699565).

Almost surely, 2^31399129 is an apocalyptic number.

It is an amenable number.

31399129 is a deficient number, since it is larger than the sum of its proper divisors (1).

31399129 is an equidigital number, since it uses as much as digits as its factorization.

31399129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13122, while the sum is 37.

The square root of 31399129 is about 5603.4925716021. The cubic root of 31399129 is about 315.4805096111.

The spelling of 31399129 in words is "thirty-one million, three hundred ninety-nine thousand, one hundred twenty-nine".