21212112121112 has 32 divisors (see below), whose sum is σ = 43400748557520. Its totient is φ = 9639127501440.

The previous prime is 21212112121099. The next prime is 21212112121147. The reversal of 21212112121112 is 21112121121212.

It is a happy number.

It is a super-2 number, since 2×21212112121112² (a number of 27 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33959303 + ... + 34578294.

Almost surely, 2^{21212112121112} is an apocalyptic number.

21212112121112 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21212112121112 is an abundant number, since it is smaller than the sum of its proper divisors (22188636436408).

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

21212112121112 is a wasteful number, since it uses less digits than its factorization.

21212112121112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68541131 (or 68541127 counting only the distinct ones).

The product of its digits is 64, while the sum is 20.

Adding to 21212112121112 its reverse (21112121121212), we get a palindrome (42324233242324).

The spelling of 21212112121112 in words is "twenty-one trillion, two hundred twelve billion, one hundred twelve million, one hundred twenty-one thousand, one hundred twelve".