21212120111103 has 40 divisors (see below), whose sum is σ = 31866009471296. Its totient is φ = 14061650673600.

The previous prime is 21212120111087. The next prime is 21212120111129. The reversal of 21212120111103 is 30111102121212.

It is a happy number.

It is not a de Polignac number, because 21212120111103 - 2⁴ = 21212120111087 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212120611103) 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, 133379613 + ... + 133538553.

Almost surely, 2^{21212120111103} is an apocalyptic number.

21212120111103 is a deficient number, since it is larger than the sum of its proper divisors (10653889360193).

21212120111103 is a wasteful number, since it uses less digits than its factorization.

21212120111103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168237 (or 168228 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 18.

Adding to 21212120111103 its reverse (30111102121212), we get a palindrome (51323222232315).

The spelling of 21212120111103 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty million, one hundred eleven thousand, one hundred three".