221911 has 6 divisors (see below), whose sum is σ = 229040. Its totient is φ = 214968.

The previous prime is 221909. The next prime is 221941. The reversal of 221911 is 119122.

It is not a de Polignac number, because 221911 - 2¹ = 221909 is a prime.

It is a Duffinian number.

221911 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221941) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 2770 + ... + 2848.

2²²¹⁹¹¹ is an apocalyptic number.

221911 is a deficient number, since it is larger than the sum of its proper divisors (7129).

221911 is an frugal number, since it uses more digits than its factorization.

221911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185 (or 132 counting only the distinct ones).

The product of its digits is 36, while the sum is 16.

The square root of 221911 is about 471.0743041177. The cubic root of 221911 is about 60.5423968016.

The spelling of 221911 in words is "two hundred twenty-one thousand, nine hundred eleven".