25688681 has 2 divisors, whose sum is σ = 25688682. Its totient is φ = 25688680.

The previous prime is 25688669. The next prime is 25688687. The reversal of 25688681 is 18688652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22657600 + 3031081 = 4760^2 + 1741^2 .

It is a cyclic number.

It is not a de Polignac number, because 25688681 - 2¹⁸ = 25426537 is a prime.

It is a super-2 number, since 2×25688681² = 1319816663039522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (25688687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12844340 + 12844341.

It is an arithmetic number, because the mean of its divisors is an integer number (12844341).

Almost surely, 2^25688681 is an apocalyptic number.

It is an amenable number.

25688681 is a deficient number, since it is larger than the sum of its proper divisors (1).

25688681 is an equidigital number, since it uses as much as digits as its factorization.

25688681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 184320, while the sum is 44.

The square root of 25688681 is about 5068.4002407071. The cubic root of 25688681 is about 295.0624439296.

The spelling of 25688681 in words is "twenty-five million, six hundred eighty-eight thousand, six hundred eighty-one".