211221001111 has 4 divisors (see below), whose sum is σ = 218034581824. Its totient is φ = 204407420400.

The previous prime is 211221001109. The next prime is 211221001153. The reversal of 211221001111 is 111100122112.

It is a happy number.

211221001111 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 211221001111 - 2¹ = 211221001109 is a prime.

It is a super-2 number, since 2×211221001111² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211221001091 and 211221001100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211221031111) 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, 3406790310 + ... + 3406790371.

It is an arithmetic number, because the mean of its divisors is an integer number (54508645456).

Almost surely, 2^211221001111 is an apocalyptic number.

211221001111 is a deficient number, since it is larger than the sum of its proper divisors (6813580713).

211221001111 is an equidigital number, since it uses as much as digits as its factorization.

211221001111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6813580712.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 211221001111 its reverse (111100122112), we get a palindrome (322321123223).

The spelling of 211221001111 in words is "two hundred eleven billion, two hundred twenty-one million, one thousand, one hundred eleven".