25621920 has 144 divisors (see below), whose sum is σ = 90810720. Its totient is φ = 6822144.

The previous prime is 25621901. The next prime is 25621927. The reversal of 25621920 is 2912652.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (25621927) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38551 + ... + 39209.

It is an arithmetic number, because the mean of its divisors is an integer number (630630).

Almost surely, 2^25621920 is an apocalyptic number.

25621920 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 25621920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45405360).

25621920 is an abundant number, since it is smaller than the sum of its proper divisors (65188800).

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

25621920 is an equidigital number, since it uses as much as digits as its factorization.

25621920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689 (or 669 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 25621920 is about 5061.8099529714. The cubic root of 25621920 is about 294.8066146130.

The spelling of 25621920 in words is "twenty-five million, six hundred twenty-one thousand, nine hundred twenty".