211220111111 has 2 divisors, whose sum is σ = 211220111112. Its totient is φ = 211220111110.

The previous prime is 211220111041. The next prime is 211220111149. The reversal of 211220111111 is 111111022112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 211220111111 - 2¹⁴ = 211220094727 is a prime.

It is a super-2 number, since 2×211220111111² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211220111171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610055555 + 105610055556.

It is an arithmetic number, because the mean of its divisors is an integer number (105610055556).

Almost surely, 2^211220111111 is an apocalyptic number.

211220111111 is a deficient number, since it is larger than the sum of its proper divisors (1).

211220111111 is an equidigital number, since it uses as much as digits as its factorization.

211220111111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 211220111111 its reverse (111111022112), we get a palindrome (322331133223).

The spelling of 211220111111 in words is "two hundred eleven billion, two hundred twenty million, one hundred eleven thousand, one hundred eleven".