313662721 has 2 divisors, whose sum is σ = 313662722. Its totient is φ = 313662720.

The previous prime is 313662719. The next prime is 313662737. The reversal of 313662721 is 127266313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 223203600 + 90459121 = 14940^2 + 9511^2 .

It is a cyclic number.

It is not a de Polignac number, because 313662721 - 2¹ = 313662719 is a prime.

Together with 313662719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (313662781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156831360 + 156831361.

It is an arithmetic number, because the mean of its divisors is an integer number (156831361).

Almost surely, 2^313662721 is an apocalyptic number.

It is an amenable number.

313662721 is a deficient number, since it is larger than the sum of its proper divisors (1).

313662721 is an equidigital number, since it uses as much as digits as its factorization.

313662721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 31.

The square root of 313662721 is about 17710.5257121295. The cubic root of 313662721 is about 679.4449919130. Note that the first 3 decimals are identical.

The spelling of 313662721 in words is "three hundred thirteen million, six hundred sixty-two thousand, seven hundred twenty-one".