815261 has 2 divisors, whose sum is σ = 815262. Its totient is φ = 815260.

The previous prime is 815257. The next prime is 815273. The reversal of 815261 is 162518.

815261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 534361 + 280900 = 731^2 + 530^2 .

It is a cyclic number.

It is not a de Polignac number, because 815261 - 2² = 815257 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (815231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 407630 + 407631.

It is an arithmetic number, because the mean of its divisors is an integer number (407631).

2⁸¹⁵²⁶¹ is an apocalyptic number.

It is an amenable number.

815261 is a deficient number, since it is larger than the sum of its proper divisors (1).

815261 is an equidigital number, since it uses as much as digits as its factorization.

815261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 480, while the sum is 23.

The square root of 815261 is about 902.9180472224. The cubic root of 815261 is about 93.4183564805.

Adding to 815261 its reverse (162518), we get a palindrome (977779).

The spelling of 815261 in words is "eight hundred fifteen thousand, two hundred sixty-one".