221144320 has 72 divisors (see below), whose sum is σ = 533005704. Its totient is φ = 87908352.

The previous prime is 221144311. The next prime is 221144321. The reversal of 221144320 is 23441122.

221144320 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 120824064 + 100320256 = 10992^2 + 10016^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221144321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 251722 + ... + 252598.

It is an arithmetic number, because the mean of its divisors is an integer number (7402857).

Almost surely, 2^221144320 is an apocalyptic number.

221144320 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 221144320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (266502852).

221144320 is an abundant number, since it is smaller than the sum of its proper divisors (311861384).

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

221144320 is an equidigital number, since it uses as much as digits as its factorization.

221144320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1095 (or 1081 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 221144320 is about 14870.9219620036. The cubic root of 221144320 is about 604.7259373862.

Adding to 221144320 its reverse (23441122), we get a palindrome (244585442).

The spelling of 221144320 in words is "two hundred twenty-one million, one hundred forty-four thousand, three hundred twenty".