221211212012 has 96 divisors (see below), whose sum is σ = 487507507200. Its totient is φ = 85634454528.

The previous prime is 221211211999. The next prime is 221211212017. The reversal of 221211212012 is 210212112122.

221211212012 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is not an unprimeable number, because it can be changed into a prime (221211212017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2257289 + ... + 2353247.

It is an arithmetic number, because the mean of its divisors is an integer number (5078203200).

Almost surely, 2^221211212012 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221211212012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (243753753600).

221211212012 is an abundant number, since it is smaller than the sum of its proper divisors (266296295188).

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

221211212012 is a wasteful number, since it uses less digits than its factorization.

221211212012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96183 (or 96181 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221211212012 its reverse (210212112122), we get a palindrome (431423324134).

The spelling of 221211212012 in words is "two hundred twenty-one billion, two hundred eleven million, two hundred twelve thousand, twelve".