311817940370921 has 2 divisors, whose sum is σ = 311817940370922. Its totient is φ = 311817940370920.

The previous prime is 311817940370863. The next prime is 311817940371071. The reversal of 311817940370921 is 129073049718113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 156543537733696 + 155274402637225 = 12511736^2 + 12460915^2 .

It is a cyclic number.

It is not a de Polignac number, because 311817940370921 - 2²⁶ = 311817873262057 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (311817940372921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155908970185460 + 155908970185461.

It is an arithmetic number, because the mean of its divisors is an integer number (155908970185461).

Almost surely, 2^{311817940370921} is an apocalyptic number.

It is an amenable number.

311817940370921 is a deficient number, since it is larger than the sum of its proper divisors (1).

311817940370921 is an equidigital number, since it uses as much as digits as its factorization.

311817940370921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2286144, while the sum is 56.

The spelling of 311817940370921 in words is "three hundred eleven trillion, eight hundred seventeen billion, nine hundred forty million, three hundred seventy thousand, nine hundred twenty-one".