313121209 has 2 divisors, whose sum is σ = 313121210. Its totient is φ = 313121208.

The previous prime is 313121203. The next prime is 313121219. The reversal of 313121209 is 902121313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 311169600 + 1951609 = 17640^2 + 1397^2 .

It is an emirp because it is prime and its reverse (902121313) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-313121209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 313121209.

It is not a weakly prime, because it can be changed into another prime (313121203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156560604 + 156560605.

It is an arithmetic number, because the mean of its divisors is an integer number (156560605).

Almost surely, 2^313121209 is an apocalyptic number.

It is an amenable number.

313121209 is a deficient number, since it is larger than the sum of its proper divisors (1).

313121209 is an equidigital number, since it uses as much as digits as its factorization.

313121209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 313121209 is about 17695.2312502550. The cubic root of 313121209 is about 679.0537653639.

The spelling of 313121209 in words is "three hundred thirteen million, one hundred twenty-one thousand, two hundred nine".