128392931 has 2 divisors, whose sum is σ = 128392932. Its totient is φ = 128392930.

The previous prime is 128392907. The next prime is 128392939. The reversal of 128392931 is 139293821.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128392931 is a prime.

It is a super-2 number, since 2×128392931² = 32969489461541522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (128392939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64196465 + 64196466.

It is an arithmetic number, because the mean of its divisors is an integer number (64196466).

Almost surely, 2^128392931 is an apocalyptic number.

128392931 is a deficient number, since it is larger than the sum of its proper divisors (1).

128392931 is an equidigital number, since it uses as much as digits as its factorization.

128392931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 38.

The square root of 128392931 is about 11331.0604534615. The cubic root of 128392931 is about 504.4835827956.

The spelling of 128392931 in words is "one hundred twenty-eight million, three hundred ninety-two thousand, nine hundred thirty-one".