212121010111 has 4 divisors (see below), whose sum is σ = 212264239824. Its totient is φ = 211977780400.

The previous prime is 212121010043. The next prime is 212121010133. The reversal of 212121010111 is 111010121212.

It is a happy number.

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 212121010111 - 2⁷ = 212121009983 is a prime.

It is a super-3 number, since 3×212121010111³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212121010091 and 212121010100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121010511) 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, 71612635 + ... + 71615596.

It is an arithmetic number, because the mean of its divisors is an integer number (53066059956).

Almost surely, 2^212121010111 is an apocalyptic number.

212121010111 is a deficient number, since it is larger than the sum of its proper divisors (143229713).

212121010111 is a wasteful number, since it uses less digits than its factorization.

212121010111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143229712.

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

Adding to 212121010111 its reverse (111010121212), we get a palindrome (323131131323).

The spelling of 212121010111 in words is "two hundred twelve billion, one hundred twenty-one million, ten thousand, one hundred eleven".