221111121 has 32 divisors (see below), whose sum is σ = 383551488. Its totient is φ = 109866240.

The previous prime is 221111063. The next prime is 221111123. The reversal of 221111121 is 121111122.

It is not a de Polignac number, because 221111121 - 2⁶ = 221111057 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221111097 and 221111106.

It is not an unprimeable number, because it can be changed into a prime (221111123) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15496 + ... + 26121.

It is an arithmetic number, because the mean of its divisors is an integer number (11985984).

Almost surely, 2^221111121 is an apocalyptic number.

221111121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221111121 is a deficient number, since it is larger than the sum of its proper divisors (162440367).

221111121 is a wasteful number, since it uses less digits than its factorization.

221111121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41661.

The product of its digits is 8, while the sum is 12.

The square root of 221111121 is about 14869.8056813127. The cubic root of 221111121 is about 604.6956746433.

Adding to 221111121 its reverse (121111122), we get a palindrome (342222243).

Subtracting from 221111121 its reverse (121111122), we obtain a palindrome (99999999).

It can be divided in two parts, 22111 and 1121, that added together give a palindrome (23232).

The spelling of 221111121 in words is "two hundred twenty-one million, one hundred eleven thousand, one hundred twenty-one".