312421309 has 2 divisors, whose sum is σ = 312421310. Its totient is φ = 312421308.

The previous prime is 312421253. The next prime is 312421327. The reversal of 312421309 is 903124213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 237252409 + 75168900 = 15403^2 + 8670^2 .

It is an emirp because it is prime and its reverse (903124213) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-312421309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (312421339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156210654 + 156210655.

It is an arithmetic number, because the mean of its divisors is an integer number (156210655).

Almost surely, 2^312421309 is an apocalyptic number.

It is an amenable number.

312421309 is a deficient number, since it is larger than the sum of its proper divisors (1).

312421309 is an equidigital number, since it uses as much as digits as its factorization.

312421309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 312421309 is about 17675.4436719422. The cubic root of 312421309 is about 678.5474393039.

The spelling of 312421309 in words is "three hundred twelve million, four hundred twenty-one thousand, three hundred nine".