315343981 has 2 divisors, whose sum is σ = 315343982. Its totient is φ = 315343980.

The previous prime is 315343949. The next prime is 315344027. The reversal of 315343981 is 189343513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 313821225 + 1522756 = 17715^2 + 1234^2 .

It is an emirp because it is prime and its reverse (189343513) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 315343981 - 2⁵ = 315343949 is a prime.

It is a super-2 number, since 2×315343981² = 198883652705856722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 315343981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (315343901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157671990 + 157671991.

It is an arithmetic number, because the mean of its divisors is an integer number (157671991).

Almost surely, 2^315343981 is an apocalyptic number.

It is an amenable number.

315343981 is a deficient number, since it is larger than the sum of its proper divisors (1).

315343981 is an equidigital number, since it uses as much as digits as its factorization.

315343981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 37.

The square root of 315343981 is about 17757.9272720664. The cubic root of 315343981 is about 680.6567911710.

The spelling of 315343981 in words is "three hundred fifteen million, three hundred forty-three thousand, nine hundred eighty-one".