25918661 has 2 divisors, whose sum is σ = 25918662. Its totient is φ = 25918660.

The previous prime is 25918649. The next prime is 25918703. The reversal of 25918661 is 16681952.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18438436 + 7480225 = 4294^2 + 2735^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25918661 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25918561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12959330 + 12959331.

It is an arithmetic number, because the mean of its divisors is an integer number (12959331).

Almost surely, 2^25918661 is an apocalyptic number.

It is an amenable number.

25918661 is a deficient number, since it is larger than the sum of its proper divisors (1).

25918661 is an equidigital number, since it uses as much as digits as its factorization.

25918661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 38.

The square root of 25918661 is about 5091.0373206253. The cubic root of 25918661 is about 295.9403527548.

The spelling of 25918661 in words is "twenty-five million, nine hundred eighteen thousand, six hundred sixty-one".