1312040309 has 2 divisors, whose sum is σ = 1312040310. Its totient is φ = 1312040308.

The previous prime is 1312040299. The next prime is 1312040339. The reversal of 1312040309 is 9030402131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 691532209 + 620508100 = 26297^2 + 24910^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312040309 - 2⁴ = 1312040293 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1312040339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656020154 + 656020155.

It is an arithmetic number, because the mean of its divisors is an integer number (656020155).

Almost surely, 2^1312040309 is an apocalyptic number.

It is an amenable number.

1312040309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312040309 is an equidigital number, since it uses as much as digits as its factorization.

1312040309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 1312040309 is about 36222.0969713240. The cubic root of 1312040309 is about 1094.7519462027.

The spelling of 1312040309 in words is "one billion, three hundred twelve million, forty thousand, three hundred nine".