311811723809 has 2 divisors, whose sum is σ = 311811723810. Its totient is φ = 311811723808.

The previous prime is 311811723757. The next prime is 311811723823. The reversal of 311811723809 is 908327118113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 200639493184 + 111172230625 = 447928^2 + 333425^2 .

It is a cyclic number.

It is not a de Polignac number, because 311811723809 - 2²⁰ = 311810675233 is a prime.

It is a super-2 number, since 2×311811723809² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 311811723809.

It is not a weakly prime, because it can be changed into another prime (311811723109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155905861904 + 155905861905.

It is an arithmetic number, because the mean of its divisors is an integer number (155905861905).

Almost surely, 2^311811723809 is an apocalyptic number.

It is an amenable number.

311811723809 is a deficient number, since it is larger than the sum of its proper divisors (1).

311811723809 is an equidigital number, since it uses as much as digits as its factorization.

311811723809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 44.

The spelling of 311811723809 in words is "three hundred eleven billion, eight hundred eleven million, seven hundred twenty-three thousand, eight hundred nine".