25540 has 12 divisors (see below), whose sum is σ = 53676. Its totient is φ = 10208.

The previous prime is 25537. The next prime is 25541. The reversal of 25540 is 4552.

25540 = T₁₁₁ + T₁₁₂ + ... + T₁₁₄.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 12996 + 12544 = 114^2 + 112^2 .

It is a nialpdrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (25541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 619 + ... + 658.

It is an arithmetic number, because the mean of its divisors is an integer number (4473).

2²⁵⁵⁴⁰ is an apocalyptic number.

25540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25540 is an abundant number, since it is smaller than the sum of its proper divisors (28136).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26838).

25540 is a wasteful number, since it uses less digits than its factorization.

25540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1286 (or 1284 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 16.

The square root of 25540 is about 159.8123900078. The cubic root of 25540 is about 29.4492087804.

It can be divided in two parts, 25 and 540, that added together give a palindrome (565).

The spelling of 25540 in words is "twenty-five thousand, five hundred forty".