212011111 has 4 divisors (see below), whose sum is σ = 228319672. Its totient is φ = 195702552.

The previous prime is 212011087. The next prime is 212011117. The reversal of 212011111 is 111110212.

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 212011111 - 2²¹ = 209913959 is a prime.

It is a super-2 number, since 2×212011111² = 89897422374908642, which contains 22 as substring.

It is a Duffinian number.

212011111 is a modest number, since divided by 11111 gives 2120 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212011117) 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, 8154261 + ... + 8154286.

It is an arithmetic number, because the mean of its divisors is an integer number (57079918).

Almost surely, 2^212011111 is an apocalyptic number.

212011111 is a deficient number, since it is larger than the sum of its proper divisors (16308561).

212011111 is a wasteful number, since it uses less digits than its factorization.

212011111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16308560.

The product of its (nonzero) digits is 4, while the sum is 10.

The square root of 212011111 is about 14560.6013268683. The cubic root of 212011111 is about 596.2836125601.

Adding to 212011111 its reverse (111110212), we get a palindrome (323121323).

It can be divided in two parts, 2120 and 11111, that added together give a palindrome (13231).

The spelling of 212011111 in words is "two hundred twelve million, eleven thousand, one hundred eleven".