21122212112 has 20 divisors (see below), whose sum is σ = 41696443980. Its totient is φ = 10361839488.

The previous prime is 21122212093. The next prime is 21122212117. The reversal of 21122212112 is 21121222112.

It can be written as a sum of positive squares in 2 ways, for example, as 17823318016 + 3298894096 = 133504^2 + 57436^2 .

It is a super-2 number, since 2×21122212112² (a number of 21 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (21122212117) 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 3 ways as a sum of consecutive naturals, for example, 12453287 + ... + 12454982.

It is an arithmetic number, because the mean of its divisors is an integer number (2084822199).

Almost surely, 2^21122212112 is an apocalyptic number.

It is an amenable number.

21122212112 is a deficient number, since it is larger than the sum of its proper divisors (20574231868).

21122212112 is a wasteful number, since it uses less digits than its factorization.

21122212112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24908330 (or 24908324 counting only the distinct ones).

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

Adding to 21122212112 its reverse (21121222112), we get a palindrome (42243434224).

The spelling of 21122212112 in words is "twenty-one billion, one hundred twenty-two million, two hundred twelve thousand, one hundred twelve".