221111121121212 has 48 divisors (see below), whose sum is σ = 589836471994112. Its totient is φ = 63152447212800.

The previous prime is 221111121121211. The next prime is 221111121121271. The reversal of 221111121121212 is 212121121111122.

It is a Harshad number since it is a multiple of its sum of digits (21).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221111121121211) 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, 461401213 + ... + 461880180.

Almost surely, 2^{221111121121212} is an apocalyptic number.

It is an amenable number.

221111121121212 is an abundant number, since it is smaller than the sum of its proper divisors (368725350872900).

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

221111121121212 is a wasteful number, since it uses less digits than its factorization.

221111121121212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 923284258 (or 923284256 counting only the distinct ones).

The product of its digits is 64, while the sum is 21.

Adding to 221111121121212 its reverse (212121121111122), we get a palindrome (433232242232334).

The spelling of 221111121121212 in words is "two hundred twenty-one trillion, one hundred eleven billion, one hundred twenty-one million, one hundred twenty-one thousand, two hundred twelve".