21222122112 has 96 divisors (see below), whose sum is σ = 61629496500. Its totient is φ = 7009099776.

The previous prime is 21222122099. The next prime is 21222122191. The reversal of 21222122112 is 21122122212.

It is a happy number.

21222122112 is a `hidden beast` number, since 212 + 221 + 221 + 12 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 21159775296 + 62346816 = 145464^2 + 7896^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

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 11 ways as a sum of consecutive naturals, for example, 41064 + ... + 210072.

Almost surely, 2^21222122112 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21222122112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30814748250).

21222122112 is an abundant number, since it is smaller than the sum of its proper divisors (40407374388).

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

21222122112 is a wasteful number, since it uses less digits than its factorization.

21222122112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169138 (or 169123 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

Adding to 21222122112 its reverse (21122122212), we get a palindrome (42344244324).

The spelling of 21222122112 in words is "twenty-one billion, two hundred twenty-two million, one hundred twenty-two thousand, one hundred twelve".