211220121111 has 16 divisors (see below), whose sum is σ = 289560380928. Its totient is φ = 136871985600.

The previous prime is 211220121109. The next prime is 211220121169. The reversal of 211220121111 is 111121022112.

It is a happy number.

211220121111 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 211220121111 - 2¹ = 211220121109 is a prime.

It is a super-2 number, since 2×211220121111² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211220121611) 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 15 ways as a sum of consecutive naturals, for example, 3135001 + ... + 3201666.

It is an arithmetic number, because the mean of its divisors is an integer number (18097523808).

Almost surely, 2^211220121111 is an apocalyptic number.

211220121111 is a deficient number, since it is larger than the sum of its proper divisors (78340259817).

211220121111 is a wasteful number, since it uses less digits than its factorization.

211220121111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6336982.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 211220121111 its reverse (111121022112), we get a palindrome (322341143223).

It can be divided in two parts, 2112201 and 21111, that added together give a palindrome (2133312).

The spelling of 211220121111 in words is "two hundred eleven billion, two hundred twenty million, one hundred twenty-one thousand, one hundred eleven".