25661717 has 2 divisors, whose sum is σ = 25661718. Its totient is φ = 25661716.

The previous prime is 25661677. The next prime is 25661719. The reversal of 25661717 is 71716652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19061956 + 6599761 = 4366^2 + 2569^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25661717 is a prime.

Together with 25661719, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25661719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12830858 + 12830859.

It is an arithmetic number, because the mean of its divisors is an integer number (12830859).

Almost surely, 2^25661717 is an apocalyptic number.

It is an amenable number.

25661717 is a deficient number, since it is larger than the sum of its proper divisors (1).

25661717 is an equidigital number, since it uses as much as digits as its factorization.

25661717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17640, while the sum is 35.

The square root of 25661717 is about 5065.7395314011. The cubic root of 25661717 is about 294.9591708312.

The spelling of 25661717 in words is "twenty-five million, six hundred sixty-one thousand, seven hundred seventeen".