25644990 has 64 divisors (see below), whose sum is σ = 72783360. Its totient is φ = 5658240.

The previous prime is 25644989. The next prime is 25645007. The reversal of 25644990 is 9944652.

It is a Curzon number.

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, 3985 + ... + 8195.

It is an arithmetic number, because the mean of its divisors is an integer number (1137240).

Almost surely, 2^25644990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25644990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36391680).

25644990 is an abundant number, since it is smaller than the sum of its proper divisors (47138370).

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

25644990 is a wasteful number, since it uses less digits than its factorization.

25644990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4257.

The product of its (nonzero) digits is 77760, while the sum is 39.

The square root of 25644990 is about 5064.0882693729. The cubic root of 25644990 is about 294.8950694511.

The spelling of 25644990 in words is "twenty-five million, six hundred forty-four thousand, nine hundred ninety".