311405309 has 2 divisors, whose sum is σ = 311405310. Its totient is φ = 311405308.

The previous prime is 311405279. The next prime is 311405327. The reversal of 311405309 is 903504113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 261307225 + 50098084 = 16165^2 + 7078^2 .

It is a cyclic number.

It is not a de Polignac number, because 311405309 - 2⁸ = 311405053 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (311405399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155702654 + 155702655.

It is an arithmetic number, because the mean of its divisors is an integer number (155702655).

Almost surely, 2^311405309 is an apocalyptic number.

It is an amenable number.

311405309 is a deficient number, since it is larger than the sum of its proper divisors (1).

311405309 is an equidigital number, since it uses as much as digits as its factorization.

311405309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 311405309 is about 17646.6798293617. The cubic root of 311405309 is about 677.8110908218.

The spelling of 311405309 in words is "three hundred eleven million, four hundred five thousand, three hundred nine".