128631331 has 2 divisors, whose sum is σ = 128631332. Its totient is φ = 128631330.

The previous prime is 128631319. The next prime is 128631337. The reversal of 128631331 is 133136821.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 128631331 - 2²³ = 120242723 is a prime.

It is a super-2 number, since 2×128631331² = 33092038629663122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 128631331.

It is not a weakly prime, because it can be changed into another prime (128631337) 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, 64315665 + 64315666.

It is an arithmetic number, because the mean of its divisors is an integer number (64315666).

Almost surely, 2^128631331 is an apocalyptic number.

128631331 is a deficient number, since it is larger than the sum of its proper divisors (1).

128631331 is an equidigital number, since it uses as much as digits as its factorization.

128631331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 28.

The square root of 128631331 is about 11341.5753314961. The cubic root of 128631331 is about 504.7956314509.

The spelling of 128631331 in words is "one hundred twenty-eight million, six hundred thirty-one thousand, three hundred thirty-one".