25649609 has 2 divisors, whose sum is σ = 25649610. Its totient is φ = 25649608.

The previous prime is 25649599. The next prime is 25649633. The reversal of 25649609 is 90694652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21827584 + 3822025 = 4672^2 + 1955^2 .

It is a cyclic number.

It is not a de Polignac number, because 25649609 - 2⁴ = 25649593 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25649699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12824804 + 12824805.

It is an arithmetic number, because the mean of its divisors is an integer number (12824805).

Almost surely, 2^25649609 is an apocalyptic number.

It is an amenable number.

25649609 is a deficient number, since it is larger than the sum of its proper divisors (1).

25649609 is an equidigital number, since it uses as much as digits as its factorization.

25649609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 41.

The square root of 25649609 is about 5064.5443032913. The cubic root of 25649609 is about 294.9127732151.

The spelling of 25649609 in words is "twenty-five million, six hundred forty-nine thousand, six hundred nine".