251221200 has 120 divisors (see below), whose sum is σ = 832610400. Its totient is φ = 64673280.

The previous prime is 251221193. The next prime is 251221213. The reversal of 251221200 is 2122152.

251221200 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×251221200² = 126224182658880000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 251221200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31191 + ... + 38409.

It is an arithmetic number, because the mean of its divisors is an integer number (6938420).

Almost surely, 2^251221200 is an apocalyptic number.

251221200 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 251221200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (416305200).

251221200 is an abundant number, since it is smaller than the sum of its proper divisors (581389200).

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

251221200 is a wasteful number, since it uses less digits than its factorization.

251221200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7269 (or 7258 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 251221200 is about 15849.9589904832. The cubic root of 251221200 is about 630.9846030050.

Adding to 251221200 its reverse (2122152), we get a palindrome (253343352).

The spelling of 251221200 in words is "two hundred fifty-one million, two hundred twenty-one thousand, two hundred".