21111100212 has 24 divisors (see below), whose sum is σ = 50590565536. Its totient is φ = 6846843168.

The previous prime is 21111100181. The next prime is 21111100289. The reversal of 21111100212 is 21200111112.

It is a super-2 number, since 2×21111100212² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23773318 + ... + 23774205.

Almost surely, 2^21111100212 is an apocalyptic number.

It is an amenable number.

21111100212 is an abundant number, since it is smaller than the sum of its proper divisors (29479465324).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21111100212 is a wasteful number, since it uses less digits than its factorization.

21111100212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47547567 (or 47547565 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21111100212 its reverse (21200111112), we get a palindrome (42311211324).

The spelling of 21111100212 in words is "twenty-one billion, one hundred eleven million, one hundred thousand, two hundred twelve".