25581500 has 48 divisors (see below), whose sum is σ = 63860160. Its totient is φ = 8769600.

The previous prime is 25581487. The next prime is 25581503. The reversal of 25581500 is 518552.

It is a self number, because there is not a number n which added to its sum of digits gives 25581500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25581503) 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, 155 + ... + 7154.

It is an arithmetic number, because the mean of its divisors is an integer number (1330420).

Almost surely, 2^25581500 is an apocalyptic number.

25581500 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 25581500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31930080).

25581500 is an abundant number, since it is smaller than the sum of its proper divisors (38278660).

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

25581500 is a wasteful number, since it uses less digits than its factorization.

25581500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7335 (or 7323 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 26.

The square root of 25581500 is about 5057.8157340892. The cubic root of 25581500 is about 294.6515084259.

The spelling of 25581500 in words is "twenty-five million, five hundred eighty-one thousand, five hundred".