221441728 has 28 divisors (see below), whose sum is σ = 465274152. Its totient is φ = 104207360.

The previous prime is 221441719. The next prime is 221441821. The reversal of 221441728 is 827144122.

221441728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 221441728.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100678 + ... + 102853.

It is an arithmetic number, because the mean of its divisors is an integer number (16616934).

Almost surely, 2^221441728 is an apocalyptic number.

It is an amenable number.

221441728 is an abundant number, since it is smaller than the sum of its proper divisors (243832424).

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

221441728 is a wasteful number, since it uses less digits than its factorization.

221441728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203560 (or 203550 counting only the distinct ones).

The product of its digits is 7168, while the sum is 31.

The square root of 221441728 is about 14880.9182512371. The cubic root of 221441728 is about 604.9969063886.

The spelling of 221441728 in words is "two hundred twenty-one million, four hundred forty-one thousand, seven hundred twenty-eight".