25131640 has 64 divisors (see below), whose sum is σ = 60134400. Its totient is φ = 9432192.

The previous prime is 25131629. The next prime is 25131671. The reversal of 25131640 is 4613152.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54049 + ... + 54511.

It is an arithmetic number, because the mean of its divisors is an integer number (939600).

Almost surely, 2^25131640 is an apocalyptic number.

25131640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25131640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30067200).

25131640 is an abundant number, since it is smaller than the sum of its proper divisors (35002760).

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

25131640 is a wasteful number, since it uses less digits than its factorization.

25131640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556 (or 552 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 25131640 is about 5013.1467163848. The cubic root of 25131640 is about 292.9140992306.

Adding to 25131640 its reverse (4613152), we get a palindrome (29744792).

The spelling of 25131640 in words is "twenty-five million, one hundred thirty-one thousand, six hundred forty".