221128 has 16 divisors (see below), whose sum is σ = 419760. Its totient is φ = 109200.

The previous prime is 221101. The next prime is 221159. The reversal of 221128 is 821122.

It is a nude number because it is divisible by every one of its digits.

It is a plaindrome in base 15.

It is an unprimeable number.

221128 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 3 ways as a sum of consecutive naturals, for example, 943 + ... + 1153.

It is an arithmetic number, because the mean of its divisors is an integer number (26235).

2²²¹¹²⁸ is an apocalyptic number.

It is an amenable number.

221128 is a deficient number, since it is larger than the sum of its proper divisors (198632).

221128 is a wasteful number, since it uses less digits than its factorization.

221128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348 (or 344 counting only the distinct ones).

The product of its digits is 64, while the sum is 16.

The square root of 221128 is about 470.2424906365. The cubic root of 221128 is about 60.4711061173.

The spelling of 221128 in words is "two hundred twenty-one thousand, one hundred twenty-eight".