25551240 has 128 divisors (see below), whose sum is σ = 90115200. Its totient is φ = 5713920.

The previous prime is 25551217. The next prime is 25551263. The reversal of 25551240 is 4215552.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (25551217) and next prime (25551263).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 25551240.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16416 + ... + 17904.

It is an arithmetic number, because the mean of its divisors is an integer number (704025).

Almost surely, 2^25551240 is an apocalyptic number.

25551240 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 25551240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45057600).

25551240 is an abundant number, since it is smaller than the sum of its proper divisors (64563960).

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

25551240 is a wasteful number, since it uses less digits than its factorization.

25551240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1527 (or 1523 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 24.

The square root of 25551240 is about 5054.8234390530. The cubic root of 25551240 is about 294.5352828650.

Adding to 25551240 its reverse (4215552), we get a palindrome (29766792).

It can be divided in two parts, 255512 and 40, that added together give a palindrome (255552).

The spelling of 25551240 in words is "twenty-five million, five hundred fifty-one thousand, two hundred forty".