25661081 has 2 divisors, whose sum is σ = 25661082. Its totient is φ = 25661080.

The previous prime is 25661071. The next prime is 25661089. The reversal of 25661081 is 18016652.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25593481 + 67600 = 5059^2 + 260^2 .

It is a cyclic number.

It is not a de Polignac number, because 25661081 - 2¹⁸ = 25398937 is a prime.

It is a super-2 number, since 2×25661081² = 1316982156177122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25661089) 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, 12830540 + 12830541.

It is an arithmetic number, because the mean of its divisors is an integer number (12830541).

Almost surely, 2^25661081 is an apocalyptic number.

It is an amenable number.

25661081 is a deficient number, since it is larger than the sum of its proper divisors (1).

25661081 is an equidigital number, since it uses as much as digits as its factorization.

25661081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 25661081 is about 5065.6767563673. The cubic root of 25661081 is about 294.9567340550.

The spelling of 25661081 in words is "twenty-five million, six hundred sixty-one thousand, eighty-one".