2561231 has 2 divisors, whose sum is σ = 2561232. Its totient is φ = 2561230.

The previous prime is 2561227. The next prime is 2561233. The reversal of 2561231 is 1321652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2561231 - 2² = 2561227 is a prime.

It is a super-2 number, since 2×2561231² = 13119808470722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 2561233, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2561233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1280615 + 1280616.

It is an arithmetic number, because the mean of its divisors is an integer number (1280616).

2^2561231 is an apocalyptic number.

2561231 is a deficient number, since it is larger than the sum of its proper divisors (1).

2561231 is an equidigital number, since it uses as much as digits as its factorization.

2561231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 20.

The square root of 2561231 is about 1600.3846412660. The cubic root of 2561231 is about 136.8199990996.

Adding to 2561231 its reverse (1321652), we get a palindrome (3882883).

The spelling of 2561231 in words is "two million, five hundred sixty-one thousand, two hundred thirty-one".