21112121121212 has 24 divisors (see below), whose sum is σ = 40305274130352. Its totient is φ = 9596343542400.

The previous prime is 21112121121199. The next prime is 21112121121229. The reversal of 21112121121212 is 21212112121112.

It is a happy number.

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, 4011338 + ... + 7636430.

It is an arithmetic number, because the mean of its divisors is an integer number (1679386422098).

Almost surely, 2^{21112121121212} is an apocalyptic number.

21112121121212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21112121121212 is a deficient number, since it is larger than the sum of its proper divisors (19193153009140).

21112121121212 is a wasteful number, since it uses less digits than its factorization.

21112121121212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3757469 (or 3757467 counting only the distinct ones).

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

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

The spelling of 21112121121212 in words is "twenty-one trillion, one hundred twelve billion, one hundred twenty-one million, one hundred twenty-one thousand, two hundred twelve".