25641440 has 96 divisors (see below), whose sum is σ = 70053984. Its totient is φ = 8765440.

The previous prime is 25641419. The next prime is 25641443. The reversal of 25641440 is 4414652.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25641443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29492 + ... + 30348.

It is an arithmetic number, because the mean of its divisors is an integer number (729729).

Almost surely, 2^25641440 is an apocalyptic number.

25641440 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 25641440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35026992).

25641440 is an abundant number, since it is smaller than the sum of its proper divisors (44412544).

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

25641440 is a wasteful number, since it uses less digits than its factorization.

25641440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900 (or 892 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 26.

The square root of 25641440 is about 5063.7377499235. The cubic root of 25641440 is about 294.8814615195.

It can be divided in two parts, 2564 and 1440, that added together give a palindrome (4004).

The spelling of 25641440 in words is "twenty-five million, six hundred forty-one thousand, four hundred forty".