25266509 has 2 divisors, whose sum is σ = 25266510. Its totient is φ = 25266508.

The previous prime is 25266497. The next prime is 25266517. The reversal of 25266509 is 90566252.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20448484 + 4818025 = 4522^2 + 2195^2 .

It is a cyclic number.

It is not a de Polignac number, because 25266509 - 2²⁰ = 24217933 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25265509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12633254 + 12633255.

It is an arithmetic number, because the mean of its divisors is an integer number (12633255).

Almost surely, 2^25266509 is an apocalyptic number.

It is an amenable number.

25266509 is a deficient number, since it is larger than the sum of its proper divisors (1).

25266509 is an equidigital number, since it uses as much as digits as its factorization.

25266509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 35.

The square root of 25266509 is about 5026.5802490361. The cubic root of 25266509 is about 293.4371394254.

The spelling of 25266509 in words is "twenty-five million, two hundred sixty-six thousand, five hundred nine".