312309919 has 2 divisors, whose sum is σ = 312309920. Its totient is φ = 312309918.

The previous prime is 312309917. The next prime is 312309923. The reversal of 312309919 is 919903213.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 312309919 - 2¹ = 312309917 is a prime.

It is a super-2 number, since 2×312309919² = 195074971011573122, which contains 22 as substring.

Together with 312309917, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (312309917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156154959 + 156154960.

It is an arithmetic number, because the mean of its divisors is an integer number (156154960).

Almost surely, 2^312309919 is an apocalyptic number.

312309919 is a deficient number, since it is larger than the sum of its proper divisors (1).

312309919 is an equidigital number, since it uses as much as digits as its factorization.

312309919 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13122, while the sum is 37.

The square root of 312309919 is about 17672.2924093056. The cubic root of 312309919 is about 678.4667871187.

The spelling of 312309919 in words is "three hundred twelve million, three hundred nine thousand, nine hundred nineteen".