25637561 has 2 divisors, whose sum is σ = 25637562. Its totient is φ = 25637560.

The previous prime is 25637551. The next prime is 25637567. The reversal of 25637561 is 16573652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20529961 + 5107600 = 4531^2 + 2260^2 .

It is a cyclic number.

It is not a de Polignac number, because 25637561 - 2¹⁰ = 25636537 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (25637567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12818780 + 12818781.

It is an arithmetic number, because the mean of its divisors is an integer number (12818781).

Almost surely, 2^25637561 is an apocalyptic number.

It is an amenable number.

25637561 is a deficient number, since it is larger than the sum of its proper divisors (1).

25637561 is an equidigital number, since it uses as much as digits as its factorization.

25637561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37800, while the sum is 35.

The square root of 25637561 is about 5063.3547179711. The cubic root of 25637561 is about 294.8665910224.

The spelling of 25637561 in words is "twenty-five million, six hundred thirty-seven thousand, five hundred sixty-one".