221111 has 4 divisors (see below), whose sum is σ = 241224. Its totient is φ = 201000.

The previous prime is 221101. The next prime is 221159. The reversal of 221111 is 111122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221111 - 2⁶ = 221047 is a prime.

It is a super-4 number, since 4×221111⁴ (a number of 22 digits) contains 4444 as substring.

It is a Duffinian number.

221111 is a modest number, since divided by 1111 gives 22 as remainder.

It is a plaindrome in base 15.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 221111.

It is not an unprimeable number, because it can be changed into a prime (221101) 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, 10040 + ... + 10061.

It is an arithmetic number, because the mean of its divisors is an integer number (60306).

2²²¹¹¹¹ is an apocalyptic number.

221111 is a deficient number, since it is larger than the sum of its proper divisors (20113).

221111 is a wasteful number, since it uses less digits than its factorization.

221111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20112.

The product of its digits is 4, while the sum is 8.

The square root of 221111 is about 470.2244145086. The cubic root of 221111 is about 60.4695564339.

Adding to 221111 its reverse (111122), we get a palindrome (332233).

It can be divided in two parts, 2211 and 11, that added together give a palindrome (2222).

The spelling of 221111 in words is "two hundred twenty-one thousand, one hundred eleven", and thus it is an iban number.