25540566 has 8 divisors (see below), whose sum is σ = 51081144. Its totient is φ = 8513520.

The previous prime is 25540549. The next prime is 25540591. The reversal of 25540566 is 66504552.

It is a happy number.

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

25540566 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2128375 + ... + 2128386.

It is an arithmetic number, because the mean of its divisors is an integer number (6385143).

Almost surely, 2^25540566 is an apocalyptic number.

25540566 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25540566 is a wasteful number, since it uses less digits than its factorization.

25540566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4256766.

The product of its (nonzero) digits is 36000, while the sum is 33.

The square root of 25540566 is about 5053.7675055349. The cubic root of 25540566 is about 294.4942632316.

It can be divided in two parts, 25540 and 566, that added together give a triangular number (26106 = T₂₂₈).

The spelling of 25540566 in words is "twenty-five million, five hundred forty thousand, five hundred sixty-six".