1311312209 has 2 divisors, whose sum is σ = 1311312210. Its totient is φ = 1311312208.

The previous prime is 1311312193. The next prime is 1311312257. The reversal of 1311312209 is 9022131131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1134342400 + 176969809 = 33680^2 + 13303^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311312209 - 2⁴ = 1311312193 is a prime.

It is not a weakly prime, because it can be changed into another prime (1311312259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655656104 + 655656105.

It is an arithmetic number, because the mean of its divisors is an integer number (655656105).

Almost surely, 2^1311312209 is an apocalyptic number.

It is an amenable number.

1311312209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311312209 is an equidigital number, since it uses as much as digits as its factorization.

1311312209 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 23.

The square root of 1311312209 is about 36212.0450817128. The cubic root of 1311312209 is about 1094.5494025316.

The spelling of 1311312209 in words is "one billion, three hundred eleven million, three hundred twelve thousand, two hundred nine".