315691 has 2 divisors, whose sum is σ = 315692. Its totient is φ = 315690.

The previous prime is 315677. The next prime is 315697. The reversal of 315691 is 196513.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 315691 - 2⁹ = 315179 is a prime.

It is not a weakly prime, because it can be changed into another prime (315697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157845 + 157846.

It is an arithmetic number, because the mean of its divisors is an integer number (157846).

2³¹⁵⁶⁹¹ is an apocalyptic number.

315691 is a deficient number, since it is larger than the sum of its proper divisors (1).

315691 is an equidigital number, since it uses as much as digits as its factorization.

315691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 810, while the sum is 25.

The square root of 315691 is about 561.8638625148. The cubic root of 315691 is about 68.0906374974.

The spelling of 315691 in words is "three hundred fifteen thousand, six hundred ninety-one".