31397129 has 2 divisors, whose sum is σ = 31397130. Its totient is φ = 31397128.

The previous prime is 31397083. The next prime is 31397143. The reversal of 31397129 is 92179313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18292729 + 13104400 = 4277^2 + 3620^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31397129 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31397159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15698564 + 15698565.

It is an arithmetic number, because the mean of its divisors is an integer number (15698565).

Almost surely, 2^31397129 is an apocalyptic number.

It is an amenable number.

31397129 is a deficient number, since it is larger than the sum of its proper divisors (1).

31397129 is an equidigital number, since it uses as much as digits as its factorization.

31397129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10206, while the sum is 35.

The square root of 31397129 is about 5603.3141086325. The cubic root of 31397129 is about 315.4738111831.

The spelling of 31397129 in words is "thirty-one million, three hundred ninety-seven thousand, one hundred twenty-nine".