221443 has 4 divisors (see below), whose sum is σ = 222640. Its totient is φ = 220248.

The previous prime is 221413. The next prime is 221447. The reversal of 221443 is 344122.

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 is a cyclic number.

It is not a de Polignac number, because 221443 - 2⁵ = 221411 is a prime.

It is a Duffinian number.

It is a plaindrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (221447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 255 + ... + 712.

It is an arithmetic number, because the mean of its divisors is an integer number (55660).

2²²¹⁴⁴³ is an apocalyptic number.

221443 is a deficient number, since it is larger than the sum of its proper divisors (1197).

221443 is an equidigital number, since it uses as much as digits as its factorization.

221443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1196.

The product of its digits is 192, while the sum is 16.

The square root of 221443 is about 470.5773050201. The cubic root of 221443 is about 60.4998064789.

Adding to 221443 its reverse (344122), we get a palindrome (565565).

It can be divided in two parts, 221 and 443, that multiplied together give a triangular number (97903 = T₄₄₂).

The spelling of 221443 in words is "two hundred twenty-one thousand, four hundred forty-three", and thus it is an iban number.