21212221112 has 32 divisors (see below), whose sum is σ = 40583980800. Its totient is φ = 10391877600.

The previous prime is 21212221061. The next prime is 21212221117. The reversal of 21212221112 is 21112221212.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212221117) by changing a digit.

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, 45314 + ... + 210897.

It is an arithmetic number, because the mean of its divisors is an integer number (1268249400).

Almost surely, 2^21212221112 is an apocalyptic number.

It is an amenable number.

21212221112 is a deficient number, since it is larger than the sum of its proper divisors (19371759688).

21212221112 is a wasteful number, since it uses less digits than its factorization.

21212221112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256427 (or 256423 counting only the distinct ones).

The product of its digits is 64, while the sum is 17.

Adding to 21212221112 its reverse (21112221212), we get a palindrome (42324442324).

The spelling of 21212221112 in words is "twenty-one billion, two hundred twelve million, two hundred twenty-one thousand, one hundred twelve".