25408640 has 96 divisors (see below), whose sum is σ = 64581300. Its totient is φ = 9547776.

The previous prime is 25408639. The next prime is 25408651. The reversal of 25408640 is 4680452.

It can be written as a sum of positive squares in 6 ways, for example, as 21752896 + 3655744 = 4664^2 + 1912^2 .

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 686702 + ... + 686738.

Almost surely, 2^25408640 is an apocalyptic number.

25408640 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 25408640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32290650).

25408640 is an abundant number, since it is smaller than the sum of its proper divisors (39172660).

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

25408640 is an equidigital number, since it uses as much as digits as its factorization.

25408640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122 (or 73 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 29.

The square root of 25408640 is about 5040.6983643142. The cubic root of 25408640 is about 293.9863322197.

The spelling of 25408640 in words is "twenty-five million, four hundred eight thousand, six hundred forty".