2561431 has 2 divisors, whose sum is σ = 2561432. Its totient is φ = 2561430.

The previous prime is 2561423. The next prime is 2561491. The reversal of 2561431 is 1341652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2561431 - 2³ = 2561423 is a prime.

It is a super-2 number, since 2×2561431² = 13121857535522, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2561401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1280715 + 1280716.

It is an arithmetic number, because the mean of its divisors is an integer number (1280716).

2^2561431 is an apocalyptic number.

2561431 is a deficient number, since it is larger than the sum of its proper divisors (1).

2561431 is an equidigital number, since it uses as much as digits as its factorization.

2561431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 22.

The square root of 2561431 is about 1600.4471250248. The cubic root of 2561431 is about 136.8235603152.

It can be divided in two parts, 2561 and 431, that added together give a palindrome (2992).

The spelling of 2561431 in words is "two million, five hundred sixty-one thousand, four hundred thirty-one".