25549 has 4 divisors (see below), whose sum is σ = 26460. Its totient is φ = 24640.

The previous prime is 25541. The next prime is 25561. The reversal of 25549 is 94552.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8649 + 16900 = 93^2 + 130^2 .

It is a cyclic number.

It is not a de Polignac number, because 25549 - 2³ = 25541 is a prime.

It is a Duffinian number.

25549 is a lucky number.

It is a congruent number.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 412 + ... + 469.

It is an arithmetic number, because the mean of its divisors is an integer number (6615).

2²⁵⁵⁴⁹ is an apocalyptic number.

25549 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

25549 is a deficient number, since it is larger than the sum of its proper divisors (911).

25549 is an equidigital number, since it uses as much as digits as its factorization.

25549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 910.

The product of its digits is 1800, while the sum is 25.

The square root of 25549 is about 159.8405455446. The cubic root of 25549 is about 29.4526675607.

The spelling of 25549 in words is "twenty-five thousand, five hundred forty-nine".