25251440 has 20 divisors (see below), whose sum is σ = 58709784. Its totient is φ = 10100544.

The previous prime is 25251407. The next prime is 25251451. The reversal of 25251440 is 4415252.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157742 + ... + 157901.

Almost surely, 2^25251440 is an apocalyptic number.

25251440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25251440 is an abundant number, since it is smaller than the sum of its proper divisors (33458344).

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

25251440 is a wasteful number, since it uses less digits than its factorization.

25251440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315656 (or 315650 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 25251440 is about 5025.0810938730. The cubic root of 25251440 is about 293.3787923119.

Adding to 25251440 its reverse (4415252), we get a palindrome (29666692).

The spelling of 25251440 in words is "twenty-five million, two hundred fifty-one thousand, four hundred forty".