221743 has 8 divisors (see below), whose sum is σ = 239616. Its totient is φ = 204600.

The previous prime is 221737. The next prime is 221747. The reversal of 221743 is 347122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-221743 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221743.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221747) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 558 + ... + 868.

It is an arithmetic number, because the mean of its divisors is an integer number (29952).

2²²¹⁷⁴³ is an apocalyptic number.

221743 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

221743 is a deficient number, since it is larger than the sum of its proper divisors (17873).

221743 is a wasteful number, since it uses less digits than its factorization.

221743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365.

The product of its digits is 336, while the sum is 19.

The square root of 221743 is about 470.8959545377. The cubic root of 221743 is about 60.5271148636.

Adding to 221743 its reverse (347122), we get a palindrome (568865).

The spelling of 221743 in words is "two hundred twenty-one thousand, seven hundred forty-three", and thus it is an iban number.