25131440 has 60 divisors (see below), whose sum is σ = 62126976. Its totient is φ = 9452544.

The previous prime is 25131437. The next prime is 25131481. The reversal of 25131440 is 4413152.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22577 + ... + 23663.

Almost surely, 2^25131440 is an apocalyptic number.

25131440 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 25131440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31063488).

25131440 is an abundant number, since it is smaller than the sum of its proper divisors (36995536).

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

25131440 is a wasteful number, since it uses less digits than its factorization.

25131440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1134 (or 1111 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 25131440 is about 5013.1267687941. The cubic root of 25131440 is about 292.9133222157.

Adding to 25131440 its reverse (4413152), we get a palindrome (29544592).

The spelling of 25131440 in words is "twenty-five million, one hundred thirty-one thousand, four hundred forty".