25815649 has 2 divisors, whose sum is σ = 25815650. Its totient is φ = 25815648.

The previous prime is 25815619. The next prime is 25815659. The reversal of 25815649 is 94651852.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24750625 + 1065024 = 4975^2 + 1032^2 .

It is a cyclic number.

It is not a de Polignac number, because 25815649 - 2⁵ = 25815617 is a prime.

It is a Chen 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, 12907824 + 12907825.

It is an arithmetic number, because the mean of its divisors is an integer number (12907825).

Almost surely, 2^25815649 is an apocalyptic number.

It is an amenable number.

25815649 is a deficient number, since it is larger than the sum of its proper divisors (1).

25815649 is an equidigital number, since it uses as much as digits as its factorization.

25815649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 86400, while the sum is 40.

The square root of 25815649 is about 5080.9102530944. The cubic root of 25815649 is about 295.5477670879.

The spelling of 25815649 in words is "twenty-five million, eight hundred fifteen thousand, six hundred forty-nine".