25861561 has 8 divisors (see below), whose sum is σ = 28253664. Its totient is φ = 23476320.

The previous prime is 25861553. The next prime is 25861643. The reversal of 25861561 is 16516852.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 25861561 - 2³ = 25861553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25861501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9250 + ... + 11716.

It is an arithmetic number, because the mean of its divisors is an integer number (3531708).

Almost surely, 2^25861561 is an apocalyptic number.

It is an amenable number.

25861561 is a deficient number, since it is larger than the sum of its proper divisors (2392103).

25861561 is a wasteful number, since it uses less digits than its factorization.

25861561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3431.

The product of its digits is 14400, while the sum is 34.

The square root of 25861561 is about 5085.4263341435. The cubic root of 25861561 is about 295.7228695739.

The spelling of 25861561 in words is "twenty-five million, eight hundred sixty-one thousand, five hundred sixty-one".