815251 has 2 divisors, whose sum is σ = 815252. Its totient is φ = 815250.

The previous prime is 815231. The next prime is 815257. The reversal of 815251 is 152518.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 815251 - 2⁷ = 815123 is a prime.

815251 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (815257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 407625 + 407626.

It is an arithmetic number, because the mean of its divisors is an integer number (407626).

2⁸¹⁵²⁵¹ is an apocalyptic number.

815251 is a deficient number, since it is larger than the sum of its proper divisors (1).

815251 is an equidigital number, since it uses as much as digits as its factorization.

815251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 400, while the sum is 22.

The square root of 815251 is about 902.9125096043. The cubic root of 815251 is about 93.4179745221.

Adding to 815251 its reverse (152518), we get a palindrome (967769).

The spelling of 815251 in words is "eight hundred fifteen thousand, two hundred fifty-one".