25540240 has 40 divisors (see below), whose sum is σ = 64781568. Its totient is φ = 9287040.

The previous prime is 25540217. The next prime is 25540243. The reversal of 25540240 is 4204552.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (25540243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13632 + ... + 15391.

Almost surely, 2^25540240 is an apocalyptic number.

25540240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25540240 is an abundant number, since it is smaller than the sum of its proper divisors (39241328).

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

25540240 is a wasteful number, since it uses less digits than its factorization.

25540240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29047 (or 29041 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 22.

The square root of 25540240 is about 5053.7352522664. The cubic root of 25540240 is about 294.4930102505.

Adding to 25540240 its reverse (4204552), we get a palindrome (29744792).

The spelling of 25540240 in words is "twenty-five million, five hundred forty thousand, two hundred forty".