221189 has 4 divisors (see below), whose sum is σ = 222156. Its totient is φ = 220224.

The previous prime is 221173. The next prime is 221197. The reversal of 221189 is 981122.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 128164 + 93025 = 358^2 + 305^2 .

It is a cyclic number.

It is not a de Polignac number, because 221189 - 2⁴ = 221173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221159) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77 + ... + 669.

It is an arithmetic number, because the mean of its divisors is an integer number (55539).

2²²¹¹⁸⁹ is an apocalyptic number.

It is an amenable number.

221189 is a deficient number, since it is larger than the sum of its proper divisors (967).

221189 is an equidigital number, since it uses as much as digits as its factorization.

221189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 966.

The product of its digits is 288, while the sum is 23.

The square root of 221189 is about 470.3073463173. The cubic root of 221189 is about 60.4766660921.

The spelling of 221189 in words is "two hundred twenty-one thousand, one hundred eighty-nine".