311211217 has 2 divisors, whose sum is σ = 311211218. Its totient is φ = 311211216.

The previous prime is 311211193. The next prime is 311211223. The reversal of 311211217 is 712112113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 250620561 + 60590656 = 15831^2 + 7784^2 .

It is a cyclic number.

It is not a de Polignac number, because 311211217 - 2²³ = 302822609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 311211194 and 311211203.

It is not a weakly prime, because it can be changed into another prime (311211227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155605608 + 155605609.

It is an arithmetic number, because the mean of its divisors is an integer number (155605609).

Almost surely, 2^311211217 is an apocalyptic number.

It is an amenable number.

311211217 is a deficient number, since it is larger than the sum of its proper divisors (1).

311211217 is an equidigital number, since it uses as much as digits as its factorization.

311211217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84, while the sum is 19.

The square root of 311211217 is about 17641.1795807423. The cubic root of 311211217 is about 677.6702400311.

The spelling of 311211217 in words is "three hundred eleven million, two hundred eleven thousand, two hundred seventeen".