25420 has 24 divisors (see below), whose sum is σ = 56448. Its totient is φ = 9600.

The previous prime is 25411. The next prime is 25423. The reversal of 25420 is 2452.

25420 = T₂₄ + T₂₅ + ... + T₅₄.

It is a happy number.

It is a nialpdrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 25420.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25423) 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 7 ways as a sum of consecutive naturals, for example, 600 + ... + 640.

It is an arithmetic number, because the mean of its divisors is an integer number (2352).

2²⁵⁴²⁰ is an apocalyptic number.

25420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28224).

25420 is an abundant number, since it is smaller than the sum of its proper divisors (31028).

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

25420 is a wasteful number, since it uses less digits than its factorization.

25420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81 (or 79 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 13.

The square root of 25420 is about 159.4365077390. The cubic root of 25420 is about 29.4030138672.

Adding to 25420 its reverse (2452), we get a palindrome (27872).

The spelling of 25420 in words is "twenty-five thousand, four hundred twenty".