25681517 has 2 divisors, whose sum is σ = 25681518. Its totient is φ = 25681516.

The previous prime is 25681507. The next prime is 25681529. The reversal of 25681517 is 71518652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25664356 + 17161 = 5066^2 + 131^2 .

It is a cyclic number.

It is not a de Polignac number, because 25681517 - 2⁸ = 25681261 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25681507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12840758 + 12840759.

It is an arithmetic number, because the mean of its divisors is an integer number (12840759).

Almost surely, 2^25681517 is an apocalyptic number.

It is an amenable number.

25681517 is a deficient number, since it is larger than the sum of its proper divisors (1).

25681517 is an equidigital number, since it uses as much as digits as its factorization.

25681517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16800, while the sum is 35.

The square root of 25681517 is about 5067.6934595534. The cubic root of 25681517 is about 295.0350126019.

The spelling of 25681517 in words is "twenty-five million, six hundred eighty-one thousand, five hundred seventeen".