311123121209 has 2 divisors, whose sum is σ = 311123121210. Its totient is φ = 311123121208.

The previous prime is 311123121193. The next prime is 311123121233. The reversal of 311123121209 is 902121321113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 303419197225 + 7703923984 = 550835^2 + 87772^2 .

It is an emirp because it is prime and its reverse (902121321113) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 311123121209 - 2⁴ = 311123121193 is a prime.

It is not a weakly prime, because it can be changed into another prime (311123421209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155561560604 + 155561560605.

It is an arithmetic number, because the mean of its divisors is an integer number (155561560605).

Almost surely, 2^311123121209 is an apocalyptic number.

It is an amenable number.

311123121209 is a deficient number, since it is larger than the sum of its proper divisors (1).

311123121209 is an equidigital number, since it uses as much as digits as its factorization.

311123121209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 26.

The spelling of 311123121209 in words is "three hundred eleven billion, one hundred twenty-three million, one hundred twenty-one thousand, two hundred nine".