221331211212 has 12 divisors (see below), whose sum is σ = 516439492856. Its totient is φ = 73777070400.

The previous prime is 221331211177. The next prime is 221331211237. The reversal of 221331211212 is 212112133122.

It is a tau number, because it is divible by the number of its divisors (12).

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9222133789 + ... + 9222133812.

Almost surely, 2^221331211212 is an apocalyptic number.

It is an amenable number.

221331211212 is an abundant number, since it is smaller than the sum of its proper divisors (295108281644).

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

221331211212 is a wasteful number, since it uses less digits than its factorization.

221331211212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18444267608 (or 18444267606 counting only the distinct ones).

The product of its digits is 288, while the sum is 21.

Adding to 221331211212 its reverse (212112133122), we get a palindrome (433443344334).

The spelling of 221331211212 in words is "two hundred twenty-one billion, three hundred thirty-one million, two hundred eleven thousand, two hundred twelve".