25530 has 32 divisors (see below), whose sum is σ = 65664. Its totient is φ = 6336.

The previous prime is 25523. The next prime is 25537. The reversal of 25530 is 3552.

25530 = 6² + 7² + ... + 42².

It is an interprime number because it is at equal distance from previous prime (25523) and next prime (25537).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25537) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 672 + ... + 708.

It is an arithmetic number, because the mean of its divisors is an integer number (2052).

2²⁵⁵³⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32832).

25530 is an abundant number, since it is smaller than the sum of its proper divisors (40134).

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

25530 is a wasteful number, since it uses less digits than its factorization.

25530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70.

The product of its (nonzero) digits is 150, while the sum is 15.

The square root of 25530 is about 159.7811002591. The cubic root of 25530 is about 29.4453647379.

It can be divided in two parts, 25 and 530, that added together give a palindrome (555).

The spelling of 25530 in words is "twenty-five thousand, five hundred thirty".