25605 has 12 divisors (see below), whose sum is σ = 44460. Its totient is φ = 13632.

The previous prime is 25603. The next prime is 25609. The reversal of 25605 is 50652.

It can be written as a sum of positive squares in 2 ways, for example, as 6561 + 19044 = 81^2 + 138^2 .

It is not a de Polignac number, because 25605 - 2¹ = 25603 is a prime.

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 240 + ... + 329.

It is an arithmetic number, because the mean of its divisors is an integer number (3705).

2²⁵⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

25605 is a deficient number, since it is larger than the sum of its proper divisors (18855).

25605 is a wasteful number, since it uses less digits than its factorization.

25605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 580 (or 577 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 25605 is about 160.0156242371. The cubic root of 25605 is about 29.4741706306.

It can be divided in two parts, 25 and 605, that added together give a triangular number (630 = T₃₅).

The spelling of 25605 in words is "twenty-five thousand, six hundred five".