21101112221212 has 12 divisors (see below), whose sum is σ = 38870469881320. Its totient is φ = 9995263683696.

The previous prime is 21101112221159. The next prime is 21101112221227. The reversal of 21101112221212 is 21212221110112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a self number, because there is not a number n which added to its sum of digits gives 21101112221212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138823106643 + ... + 138823106794.

Almost surely, 2^{21101112221212} is an apocalyptic number.

It is an amenable number.

21101112221212 is a deficient number, since it is larger than the sum of its proper divisors (17769357660108).

21101112221212 is a wasteful number, since it uses less digits than its factorization.

21101112221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277646213460 (or 277646213458 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21101112221212 its reverse (21212221110112), we get a palindrome (42313333331324).

Subtracting 21101112221212 from its reverse (21212221110112), we obtain a square (111108888900 = 333330²).

The spelling of 21101112221212 in words is "twenty-one trillion, one hundred one billion, one hundred twelve million, two hundred twenty-one thousand, two hundred twelve".