25581980 has 48 divisors (see below), whose sum is σ = 59028480. Its totient is φ = 9269568.

The previous prime is 25581979. The next prime is 25581989. The reversal of 25581980 is 8918552.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25581989) 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, 7277 + ... + 10203.

It is an arithmetic number, because the mean of its divisors is an integer number (1229760).

Almost surely, 2^25581980 is an apocalyptic number.

25581980 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 25581980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29514240).

25581980 is an abundant number, since it is smaller than the sum of its proper divisors (33446500).

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

25581980 is a wasteful number, since it uses less digits than its factorization.

25581980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2978 (or 2976 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 38.

The square root of 25581980 is about 5057.8631851801. The cubic root of 25581980 is about 294.6533513180.

The spelling of 25581980 in words is "twenty-five million, five hundred eighty-one thousand, nine hundred eighty".