313921 has 2 divisors, whose sum is σ = 313922. Its totient is φ = 313920.

The previous prime is 313909. The next prime is 313931. The reversal of 313921 is 129313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 230400 + 83521 = 480^2 + 289^2 .

It is an emirp because it is prime and its reverse (129313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 313921 - 2⁵ = 313889 is a prime.

It is equal to p₂₇₁₀₉ and since 313921 and 27109 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (313931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156960 + 156961.

It is an arithmetic number, because the mean of its divisors is an integer number (156961).

2³¹³⁹²¹ is an apocalyptic number.

It is an amenable number.

313921 is a deficient number, since it is larger than the sum of its proper divisors (1).

313921 is an equidigital number, since it uses as much as digits as its factorization.

313921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 162, while the sum is 19.

The square root of 313921 is about 560.2865338378. The cubic root of 313921 is about 67.9631432333.

It can be divided in two parts, 3139 and 21, that added together give a triangular number (3160 = T₇₉).

The spelling of 313921 in words is "three hundred thirteen thousand, nine hundred twenty-one".