221011111111121 has 4 divisors (see below), whose sum is σ = 221011180133232. Its totient is φ = 221011042089012.

The previous prime is 221011111111081. The next prime is 221011111111123. The reversal of 221011111111121 is 121111111110122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221011111111121 is a prime.

It is a super-2 number, since 2×221011111111121² (a number of 29 digits) contains 22 as substring.

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 221011111111121.

It is not an unprimeable number, because it can be changed into a prime (221011111111123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29461751 + ... + 36194156.

It is an arithmetic number, because the mean of its divisors is an integer number (55252795033308).

Almost surely, 2^{221011111111121} is an apocalyptic number.

It is an amenable number.

221011111111121 is a deficient number, since it is larger than the sum of its proper divisors (69022111).

221011111111121 is an equidigital number, since it uses as much as digits as its factorization.

221011111111121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69022110.

The product of its (nonzero) digits is 8, while the sum is 17.

Adding to 221011111111121 its reverse (121111111110122), we get a palindrome (342122222221243).

Subtracting from 221011111111121 its reverse (121111111110122), we obtain a palindrome (99900000000999).

The spelling of 221011111111121 in words is "two hundred twenty-one trillion, eleven billion, one hundred eleven million, one hundred eleven thousand, one hundred twenty-one".