1315891 has 2 divisors, whose sum is σ = 1315892. Its totient is φ = 1315890.

The previous prime is 1315889. The next prime is 1315901. The reversal of 1315891 is 1985131.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1315891 - 2¹ = 1315889 is a prime.

Together with 1315889, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1315801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 657945 + 657946.

It is an arithmetic number, because the mean of its divisors is an integer number (657946).

2^1315891 is an apocalyptic number.

1315891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1315891 is an equidigital number, since it uses as much as digits as its factorization.

1315891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 28.

The square root of 1315891 is about 1147.1229227942. The cubic root of 1315891 is about 109.5821891511.

It can be divided in two parts, 13158 and 91, that multiplied together give a triangular number (1197378 = T₁₅₄₇).

The spelling of 1315891 in words is "one million, three hundred fifteen thousand, eight hundred ninety-one".