251325440 has 88 divisors (see below), whose sum is σ = 608401152. Its totient is φ = 99614720.

The previous prime is 251325421. The next prime is 251325461. The reversal of 251325440 is 44523152.

It is a happy number.

251325440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 977792 + ... + 978048.

Almost surely, 2^251325440 is an apocalyptic number.

251325440 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 251325440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (304200576).

251325440 is an abundant number, since it is smaller than the sum of its proper divisors (357075712).

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

251325440 is a wasteful number, since it uses less digits than its factorization.

251325440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473 (or 455 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 26.

The square root of 251325440 is about 15853.2469860278. The cubic root of 251325440 is about 631.0718630768.

Adding to 251325440 its reverse (44523152), we get a palindrome (295848592).

The spelling of 251325440 in words is "two hundred fifty-one million, three hundred twenty-five thousand, four hundred forty".