313813921 has 2 divisors, whose sum is σ = 313813922. Its totient is φ = 313813920.

The previous prime is 313813919. The next prime is 313813939. The reversal of 313813921 is 129318313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 226653025 + 87160896 = 15055^2 + 9336^2 .

It is a cyclic number.

It is not a de Polignac number, because 313813921 - 2¹ = 313813919 is a prime.

Together with 313813919, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (313813121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156906960 + 156906961.

It is an arithmetic number, because the mean of its divisors is an integer number (156906961).

Almost surely, 2^313813921 is an apocalyptic number.

It is an amenable number.

313813921 is a deficient number, since it is larger than the sum of its proper divisors (1).

313813921 is an equidigital number, since it uses as much as digits as its factorization.

313813921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 31.

The square root of 313813921 is about 17714.7938458228. The cubic root of 313813921 is about 679.5541490565.

The spelling of 313813921 in words is "three hundred thirteen million, eight hundred thirteen thousand, nine hundred twenty-one".