251530224 has 80 divisors (see below), whose sum is σ = 733345920. Its totient is φ = 73588480.

The previous prime is 251530211. The next prime is 251530259. The reversal of 251530224 is 422035152.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 251530194 and 251530203.

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, 7099 + ... + 23525.

It is an arithmetic number, because the mean of its divisors is an integer number (9166824).

Almost surely, 2^251530224 is an apocalyptic number.

251530224 is a gapful number since it is divisible by the number (24) 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 251530224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (366672960).

251530224 is an abundant number, since it is smaller than the sum of its proper divisors (481815696).

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

251530224 is a wasteful number, since it uses less digits than its factorization.

251530224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16478 (or 16472 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 251530224 is about 15859.7044108647. The cubic root of 251530224 is about 631.2432190364.

Adding to 251530224 its reverse (422035152), we get a palindrome (673565376).

The spelling of 251530224 in words is "two hundred fifty-one million, five hundred thirty thousand, two hundred twenty-four".