25815689 has 2 divisors, whose sum is σ = 25815690. Its totient is φ = 25815688.

The previous prime is 25815659. The next prime is 25815697. The reversal of 25815689 is 98651852.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16000000 + 9815689 = 4000^2 + 3133^2 .

It is a cyclic number.

It is not a de Polignac number, because 25815689 - 2²⁴ = 9038473 is a prime.

It is not a weakly prime, because it can be changed into another prime (25815619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12907844 + 12907845.

It is an arithmetic number, because the mean of its divisors is an integer number (12907845).

Almost surely, 2^25815689 is an apocalyptic number.

It is an amenable number.

25815689 is a deficient number, since it is larger than the sum of its proper divisors (1).

25815689 is an equidigital number, since it uses as much as digits as its factorization.

25815689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 172800, while the sum is 44.

The square root of 25815689 is about 5080.9141893954. The cubic root of 25815689 is about 295.5479197331.

The spelling of 25815689 in words is "twenty-five million, eight hundred fifteen thousand, six hundred eighty-nine".