25442809 has 24 divisors (see below), whose sum is σ = 30767688. Its totient is φ = 20966400.

The previous prime is 25442803. The next prime is 25442821. The reversal of 25442809 is 90824452.

It can be written as a sum of positive squares in 4 ways, for example, as 12446784 + 12996025 = 3528^2 + 3605^2 .

It is not a de Polignac number, because 25442809 - 2⁵ = 25442777 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25442803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 251859 + ... + 251959.

It is an arithmetic number, because the mean of its divisors is an integer number (1281987).

Almost surely, 2^25442809 is an apocalyptic number.

It is an amenable number.

25442809 is a deficient number, since it is larger than the sum of its proper divisors (5324879).

25442809 is a wasteful number, since it uses less digits than its factorization.

25442809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265 (or 258 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 25442809 is about 5044.0865377192. The cubic root of 25442809 is about 294.1180553853.

The spelling of 25442809 in words is "twenty-five million, four hundred forty-two thousand, eight hundred nine".