211111101111111 has 4 divisors (see below), whose sum is σ = 281481468148152. Its totient is φ = 140740734074072.

The previous prime is 211111101111073. The next prime is 211111101111121. The reversal of 211111101111111 is 111111101111112.

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 211111101111111 - 2²¹ = 211111099013959 is a prime.

It is a super-3 number, since 3×211111101111111³ (a number of 44 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211111101111121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35185183518516 + ... + 35185183518521.

It is an arithmetic number, because the mean of its divisors is an integer number (70370367037038).

Almost surely, 2^{211111101111111} is an apocalyptic number.

211111101111111 is a deficient number, since it is larger than the sum of its proper divisors (70370367037041).

211111101111111 is an equidigital number, since it uses as much as digits as its factorization.

211111101111111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70370367037040.

The product of its (nonzero) digits is 2, while the sum is 15.

Adding to 211111101111111 its reverse (111111101111112), we get a palindrome (322222202222223).

Subtracting from 211111101111111 its reverse (111111101111112), we obtain a palindrome (99999999999999).

The spelling of 211111101111111 in words is "two hundred eleven trillion, one hundred eleven billion, one hundred one million, one hundred eleven thousand, one hundred eleven".