21221110112212 has 48 divisors (see below), whose sum is σ = 40074883192512. Its totient is φ = 9795169579520.

The previous prime is 21221110112201. The next prime is 21221110112219. The reversal of 21221110112212 is 21221101112212.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21221110112212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221110112219) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11738223 + ... + 13424905.

It is an arithmetic number, because the mean of its divisors is an integer number (834893399844).

Almost surely, 2^{21221110112212} is an apocalyptic number.

It is an amenable number.

21221110112212 is a deficient number, since it is larger than the sum of its proper divisors (18853773080300).

21221110112212 is a wasteful number, since it uses less digits than its factorization.

21221110112212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1690248 (or 1690246 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21221110112212 its reverse (21221101112212), we get a palindrome (42442211224424).

Subtracting from 21221110112212 its reverse (21221101112212), we obtain a square (9000000 = 3000²).

The spelling of 21221110112212 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred ten million, one hundred twelve thousand, two hundred twelve".