25540040 has 16 divisors (see below), whose sum is σ = 57465180. Its totient is φ = 10216000.

The previous prime is 25540037. The next prime is 25540043. The reversal of 25540040 is 4004552.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (25540037) and next prime (25540043).

It can be written as a sum of positive squares in 2 ways, for example, as 23174596 + 2365444 = 4814^2 + 1538^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 25539994 and 25540021.

It is not an unprimeable number, because it can be changed into a prime (25540043) 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, 319211 + ... + 319290.

Almost surely, 2^25540040 is an apocalyptic number.

25540040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25540040 is an abundant number, since it is smaller than the sum of its proper divisors (31925140).

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

25540040 is a wasteful number, since it uses less digits than its factorization.

25540040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 638512 (or 638508 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 20.

The square root of 25540040 is about 5053.7154648832. The cubic root of 25540040 is about 294.4922415452.

Adding to 25540040 its reverse (4004552), we get a palindrome (29544592).

The spelling of 25540040 in words is "twenty-five million, five hundred forty thousand, forty".