251225240 has 128 divisors (see below), whose sum is σ = 675717120. Its totient is φ = 82252800.

The previous prime is 251225197. The next prime is 251225243. The reversal of 251225240 is 42522152.

It is a super-2 number, since 2×251225240² = 126228242426115200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251225243) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 893900 + ... + 894180.

It is an arithmetic number, because the mean of its divisors is an integer number (5279040).

Almost surely, 2^251225240 is an apocalyptic number.

251225240 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 251225240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (337858560).

251225240 is an abundant number, since it is smaller than the sum of its proper divisors (424491880).

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

251225240 is a wasteful number, since it uses less digits than its factorization.

251225240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433 (or 429 counting only the distinct ones).

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

The square root of 251225240 is about 15850.0864350956. The cubic root of 251225240 is about 630.9879853684.

Adding to 251225240 its reverse (42522152), we get a palindrome (293747392).

The spelling of 251225240 in words is "two hundred fifty-one million, two hundred twenty-five thousand, two hundred forty".