212121201021111 has 24 divisors (see below), whose sum is σ = 319836958868544. Its totient is φ = 135336521684160.

The previous prime is 212121201021101. The next prime is 212121201021127. The reversal of 212121201021111 is 111120102121212.

It is a happy number.

212121201021111 is a `hidden beast` number, since 212 + 121 + 201 + 0 + 21 + 111 = 666.

It is not a de Polignac number, because 212121201021111 - 2¹⁰ = 212121201020087 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121201021101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5221296111 + ... + 5221336736.

It is an arithmetic number, because the mean of its divisors is an integer number (13326539952856).

Almost surely, 2^{212121201021111} is an apocalyptic number.

212121201021111 is a deficient number, since it is larger than the sum of its proper divisors (107715757847433).

212121201021111 is a wasteful number, since it uses less digits than its factorization.

212121201021111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10442632951 (or 10442632948 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 212121201021111 its reverse (111120102121212), we get a palindrome (323241303142323).

The spelling of 212121201021111 in words is "two hundred twelve trillion, one hundred twenty-one billion, two hundred one million, twenty-one thousand, one hundred eleven".