311211491 has 2 divisors, whose sum is σ = 311211492. Its totient is φ = 311211490.

The previous prime is 311211479. The next prime is 311211517. The reversal of 311211491 is 194112113.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 311211491 - 2⁶ = 311211427 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (311211451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155605745 + 155605746.

It is an arithmetic number, because the mean of its divisors is an integer number (155605746).

Almost surely, 2^311211491 is an apocalyptic number.

311211491 is a deficient number, since it is larger than the sum of its proper divisors (1).

311211491 is an equidigital number, since it uses as much as digits as its factorization.

311211491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 23.

The square root of 311211491 is about 17641.1873466612. The cubic root of 311211491 is about 677.6704389117.

The spelling of 311211491 in words is "three hundred eleven million, two hundred eleven thousand, four hundred ninety-one".