25809920 has 66 divisors (see below), whose sum is σ = 62797866. Its totient is φ = 10178560.

The previous prime is 25809919. The next prime is 25809967. The reversal of 25809920 is 2990852.

It can be written as a sum of positive squares in only one way, i.e., 20647936 + 5161984 = 4544^2 + 2272^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 363485 + ... + 363555.

Almost surely, 2^25809920 is an apocalyptic number.

25809920 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 25809920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31398933).

25809920 is an abundant number, since it is smaller than the sum of its proper divisors (36987946).

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

25809920 is an frugal number, since it uses more digits than its factorization.

25809920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 25809920 is about 5080.3464448795. The cubic root of 25809920 is about 295.5259028506.

The spelling of 25809920 in words is "twenty-five million, eight hundred nine thousand, nine hundred twenty".