25281540 has 36 divisors (see below), whose sum is σ = 76687884. Its totient is φ = 6741696.

The previous prime is 25281527. The next prime is 25281541. The reversal of 25281540 is 4518252.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14152644 + 11128896 = 3762^2 + 3336^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (25281541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70047 + ... + 70406.

It is an arithmetic number, because the mean of its divisors is an integer number (2130219).

Almost surely, 2^25281540 is an apocalyptic number.

25281540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25281540 is an abundant number, since it is smaller than the sum of its proper divisors (51406344).

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

25281540 is a wasteful number, since it uses less digits than its factorization.

25281540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140468 (or 140463 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 25281540 is about 5028.0751784356. The cubic root of 25281540 is about 293.4953162963.

Adding to 25281540 its reverse (4518252), we get a palindrome (29799792).

The spelling of 25281540 in words is "twenty-five million, two hundred eighty-one thousand, five hundred forty".