25779520 has 56 divisors (see below), whose sum is σ = 66120264. Its totient is φ = 9517056.

The previous prime is 25779511. The next prime is 25779539. The reversal of 25779520 is 2597752.

It can be written as a sum of positive squares in 4 ways, for example, as 135424 + 25644096 = 368^2 + 5064^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 25779520.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1062 + ... + 7258.

It is an arithmetic number, because the mean of its divisors is an integer number (1180719).

Almost surely, 2^25779520 is an apocalyptic number.

25779520 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 25779520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33060132).

25779520 is an abundant number, since it is smaller than the sum of its proper divisors (40340744).

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

25779520 is a wasteful number, since it uses less digits than its factorization.

25779520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6227 (or 6217 counting only the distinct ones).

The product of its (nonzero) digits is 44100, while the sum is 37.

The square root of 25779520 is about 5077.3536414160. The cubic root of 25779520 is about 295.4098296897.

The spelling of 25779520 in words is "twenty-five million, seven hundred seventy-nine thousand, five hundred twenty".