313981 has 2 divisors, whose sum is σ = 313982. Its totient is φ = 313980.

The previous prime is 313979. The next prime is 313987. The reversal of 313981 is 189313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 241081 + 72900 = 491^2 + 270^2 .

It is a cyclic number.

It is not a de Polignac number, because 313981 - 2¹ = 313979 is a prime.

It is a super-2 number, since 2×313981² = 197168136722, which contains 22 as substring.

Together with 313979, it forms a pair of twin primes.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (313987) 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, 156990 + 156991.

It is an arithmetic number, because the mean of its divisors is an integer number (156991).

2³¹³⁹⁸¹ is an apocalyptic number.

It is an amenable number.

313981 is a deficient number, since it is larger than the sum of its proper divisors (1).

313981 is an equidigital number, since it uses as much as digits as its factorization.

313981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 648, while the sum is 25.

The square root of 313981 is about 560.3400753114. The cubic root of 313981 is about 67.9674729095.

The spelling of 313981 in words is "three hundred thirteen thousand, nine hundred eighty-one".