212111221212 has 72 divisors (see below), whose sum is σ = 606576227712. Its totient is φ = 64276124400.

The previous prime is 212111221211. The next prime is 212111221297. The reversal of 212111221212 is 212122111212.

212111221212 is a `hidden beast` number, since 21 + 211 + 1 + 221 + 212 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

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 (212111221211) 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 23 ways as a sum of consecutive naturals, for example, 9908464 + ... + 9929847.

Almost surely, 2^212111221212 is an apocalyptic number.

212111221212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

212111221212 is an abundant number, since it is smaller than the sum of its proper divisors (394465006500).

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

212111221212 is a wasteful number, since it uses less digits than its factorization.

212111221212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19838341 (or 19838327 counting only the distinct ones).

The product of its digits is 64, while the sum is 18.

Adding to 212111221212 its reverse (212122111212), we get a palindrome (424233332424).

Subtracting 212111221212 from its reverse (212122111212), we obtain a square (10890000 = 3300²).

The spelling of 212111221212 in words is "two hundred twelve billion, one hundred eleven million, two hundred twenty-one thousand, two hundred twelve".