25815617 has 2 divisors, whose sum is σ = 25815618. Its totient is φ = 25815616.

The previous prime is 25815613. The next prime is 25815619. The reversal of 25815617 is 71651852.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18627856 + 7187761 = 4316^2 + 2681^2 .

It is a cyclic number.

It is not a de Polignac number, because 25815617 - 2² = 25815613 is a prime.

Together with 25815619, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25815613) 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, 12907808 + 12907809.

It is an arithmetic number, because the mean of its divisors is an integer number (12907809).

Almost surely, 2^25815617 is an apocalyptic number.

It is an amenable number.

25815617 is a deficient number, since it is larger than the sum of its proper divisors (1).

25815617 is an equidigital number, since it uses as much as digits as its factorization.

25815617 is an odious number, because the sum of its binary digits is odd.

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

The square root of 25815617 is about 5080.9071040514. The cubic root of 25815617 is about 295.5476449716.

The spelling of 25815617 in words is "twenty-five million, eight hundred fifteen thousand, six hundred seventeen".