311328991 has 2 divisors, whose sum is σ = 311328992. Its totient is φ = 311328990.

The previous prime is 311328937. The next prime is 311329043. The reversal of 311328991 is 199823113.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-311328991 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 311328991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (311328491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155664495 + 155664496.

It is an arithmetic number, because the mean of its divisors is an integer number (155664496).

Almost surely, 2^311328991 is an apocalyptic number.

311328991 is a deficient number, since it is larger than the sum of its proper divisors (1).

311328991 is an equidigital number, since it uses as much as digits as its factorization.

311328991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 37.

The square root of 311328991 is about 17644.5173070844. The cubic root of 311328991 is about 677.7557145306.

The spelling of 311328991 in words is "three hundred eleven million, three hundred twenty-eight thousand, nine hundred ninety-one".