25551540 has 108 divisors (see below), whose sum is σ = 90191556. Its totient is φ = 5838336.

The previous prime is 25551521. The next prime is 25551541. The reversal of 25551540 is 4515552.

It can be written as a sum of positive squares in 2 ways, for example, as 5731236 + 19820304 = 2394^2 + 4452^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25551541) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 7372 + ... + 10268.

It is an arithmetic number, because the mean of its divisors is an integer number (835107).

Almost surely, 2^25551540 is an apocalyptic number.

25551540 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 25551540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45095778).

25551540 is an abundant number, since it is smaller than the sum of its proper divisors (64640016).

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

25551540 is a wasteful number, since it uses less digits than its factorization.

25551540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2926 (or 2914 counting only the distinct ones).

The product of its (nonzero) digits is 5000, while the sum is 27.

The square root of 25551540 is about 5054.8531135929. The cubic root of 25551540 is about 294.5364355845.

It can be divided in two parts, 2555 and 1540, that added together give a triangular number (4095 = T₉₀).

The spelling of 25551540 in words is "twenty-five million, five hundred fifty-one thousand, five hundred forty".