201221111 has 16 divisors (see below), whose sum is σ = 256200000. Its totient is φ = 153715968.

The previous prime is 201221101. The next prime is 201221113. The reversal of 201221111 is 111122102.

It is a de Polignac number, because none of the positive numbers 2^k-201221111 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 201221092 and 201221101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221113) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35486 + ... + 40763.

It is an arithmetic number, because the mean of its divisors is an integer number (16012500).

Almost surely, 2^201221111 is an apocalyptic number.

201221111 is a deficient number, since it is larger than the sum of its proper divisors (54978889).

201221111 is a wasteful number, since it uses less digits than its factorization.

201221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76298.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 201221111 is about 14185.2427191078. The cubic root of 201221111 is about 585.9913169902.

Adding to 201221111 its reverse (111122102), we get a palindrome (312343213).

Subtracting from 201221111 its reverse (111122102), we obtain a palindrome (90099009).

The spelling of 201221111 in words is "two hundred one million, two hundred twenty-one thousand, one hundred eleven".