311320991 has 2 divisors, whose sum is σ = 311320992. Its totient is φ = 311320990.

The previous prime is 311320987. The next prime is 311321011. The reversal of 311320991 is 199023113.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 311320991 - 2² = 311320987 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (311320901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155660495 + 155660496.

It is an arithmetic number, because the mean of its divisors is an integer number (155660496).

Almost surely, 2^311320991 is an apocalyptic number.

311320991 is a deficient number, since it is larger than the sum of its proper divisors (1).

311320991 is an equidigital number, since it uses as much as digits as its factorization.

311320991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1458, while the sum is 29.

The square root of 311320991 is about 17644.2906063123. The cubic root of 311320991 is about 677.7499092118.

The spelling of 311320991 in words is "three hundred eleven million, three hundred twenty thousand, nine hundred ninety-one".