25491 has 8 divisors (see below), whose sum is σ = 35280. Its totient is φ = 16352.

The previous prime is 25471. The next prime is 25523. The reversal of 25491 is 19452.

25491 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

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 25491 - 2⁹ = 24979 is a prime.

It is a super-3 number, since 3×25491³ = 49691473337313, which contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (25411) 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, 60 + ... + 233.

It is an arithmetic number, because the mean of its divisors is an integer number (4410).

2²⁵⁴⁹¹ is an apocalyptic number.

25491 is a deficient number, since it is larger than the sum of its proper divisors (9789).

25491 is a wasteful number, since it uses less digits than its factorization.

25491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325.

The product of its digits is 360, while the sum is 21.

The square root of 25491 is about 159.6590116467. The cubic root of 25491 is about 29.4303633738.

The spelling of 25491 in words is "twenty-five thousand, four hundred ninety-one".