25540840 has 32 divisors (see below), whose sum is σ = 61888680. Its totient is φ = 9430272.

The previous prime is 25540829. The next prime is 25540847. The reversal of 25540840 is 4804552.

It can be written as a sum of positive squares in 4 ways, for example, as 21288996 + 4251844 = 4614^2 + 2062^2 .

It is a junction number, because it is equal to n+sod(n) for n = 25540799 and 25540808.

It is not an unprimeable number, because it can be changed into a prime (25540847) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24039 + ... + 25078.

Almost surely, 2^25540840 is an apocalyptic number.

25540840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25540840 is an abundant number, since it is smaller than the sum of its proper divisors (36347840).

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

25540840 is a wasteful number, since it uses less digits than its factorization.

25540840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49141 (or 49137 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 28.

The square root of 25540840 is about 5053.7946139510. The cubic root of 25540840 is about 294.4953163424.

The spelling of 25540840 in words is "twenty-five million, five hundred forty thousand, eight hundred forty".