815257 has 2 divisors, whose sum is σ = 815258. Its totient is φ = 815256.

The previous prime is 815251. The next prime is 815261. The reversal of 815257 is 752518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 808201 + 7056 = 899^2 + 84^2 .

It is a cyclic number.

It is not a de Polignac number, because 815257 - 2¹¹ = 813209 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (815251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 407628 + 407629.

It is an arithmetic number, because the mean of its divisors is an integer number (407629).

2⁸¹⁵²⁵⁷ is an apocalyptic number.

It is an amenable number.

815257 is a deficient number, since it is larger than the sum of its proper divisors (1).

815257 is an equidigital number, since it uses as much as digits as its factorization.

815257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2800, while the sum is 28.

The square root of 815257 is about 902.9158321793. The cubic root of 815257 is about 93.4182036975.

The spelling of 815257 in words is "eight hundred fifteen thousand, two hundred fifty-seven".