25644040 has 16 divisors (see below), whose sum is σ = 57699180. Its totient is φ = 10257600.

The previous prime is 25644029. The next prime is 25644043. The reversal of 25644040 is 4044652.

It can be written as a sum of positive squares in 2 ways, for example, as 25542916 + 101124 = 5054^2 + 318^2 .

It is a junction number, because it is equal to n+sod(n) for n = 25643996 and 25644014.

It is not an unprimeable number, because it can be changed into a prime (25644043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 320511 + ... + 320590.

Almost surely, 2^25644040 is an apocalyptic number.

25644040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25644040 is an abundant number, since it is smaller than the sum of its proper divisors (32055140).

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

25644040 is a wasteful number, since it uses less digits than its factorization.

25644040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641112 (or 641108 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 25.

The square root of 25644040 is about 5063.9944707711. The cubic root of 25644040 is about 294.8914280150.

Adding to 25644040 its reverse (4044652), we get a palindrome (29688692).

The spelling of 25644040 in words is "twenty-five million, six hundred forty-four thousand, forty".