313105981 has 2 divisors, whose sum is σ = 313105982. Its totient is φ = 313105980.

The previous prime is 313105967. The next prime is 313105987. The reversal of 313105981 is 189501313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 228281881 + 84824100 = 15109^2 + 9210^2 .

It is an emirp because it is prime and its reverse (189501313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 313105981 - 2¹¹ = 313103933 is a prime.

It is a super-2 number, since 2×313105981² = 196070710675944722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (313105987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156552990 + 156552991.

It is an arithmetic number, because the mean of its divisors is an integer number (156552991).

Almost surely, 2^313105981 is an apocalyptic number.

It is an amenable number.

313105981 is a deficient number, since it is larger than the sum of its proper divisors (1).

313105981 is an equidigital number, since it uses as much as digits as its factorization.

313105981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 313105981 is about 17694.8009596039. The cubic root of 313105981 is about 679.0427570621.

The spelling of 313105981 in words is "three hundred thirteen million, one hundred five thousand, nine hundred eighty-one".