25131609 has 6 divisors (see below), whose sum is σ = 36301226. Its totient is φ = 16754400.

The previous prime is 25131583. The next prime is 25131611. The reversal of 25131609 is 90613152.

25131609 is a `hidden beast` number, since 2 + 51 + 3 + 1 + 609 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21902400 + 3229209 = 4680^2 + 1797^2 .

It is not a de Polignac number, because 25131609 - 2⁷ = 25131481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25131629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1396192 + ... + 1396209.

Almost surely, 2^25131609 is an apocalyptic number.

It is an amenable number.

25131609 is a deficient number, since it is larger than the sum of its proper divisors (11169617).

25131609 is a wasteful number, since it uses less digits than its factorization.

25131609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2792407 (or 2792404 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 25131609 is about 5013.1436245135. The cubic root of 25131609 is about 292.9139787936.

The spelling of 25131609 in words is "twenty-five million, one hundred thirty-one thousand, six hundred nine".