20212121211111 has 40 divisors (see below), whose sum is σ = 30265740212400. Its totient is φ = 13442475771648.

The previous prime is 20212121211053. The next prime is 20212121211119. The reversal of 20212121211111 is 11111212121202.

It is a happy number.

20212121211111 is a `hidden beast` number, since 202 + 121 + 21 + 211 + 111 = 666.

It is not a de Polignac number, because 20212121211111 - 2¹⁵ = 20212121178343 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20212121211119) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 662829381 + ... + 662859873.

It is an arithmetic number, because the mean of its divisors is an integer number (756643505310).

Almost surely, 2^{20212121211111} is an apocalyptic number.

20212121211111 is a deficient number, since it is larger than the sum of its proper divisors (10053619001289).

20212121211111 is a wasteful number, since it uses less digits than its factorization.

20212121211111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49837 (or 49828 counting only the distinct ones).

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

Adding to 20212121211111 its reverse (11111212121202), we get a palindrome (31323333332313).

It can be divided in two parts, 2021212 and 1211111, that added together give a palindrome (3232323).

The spelling of 20212121211111 in words is "twenty trillion, two hundred twelve billion, one hundred twenty-one million, two hundred eleven thousand, one hundred eleven".