221221121212 has 48 divisors (see below), whose sum is σ = 476535270400. Its totient is φ = 87505209792.

The previous prime is 221221121197. The next prime is 221221121267. The reversal of 221221121212 is 212121122122.

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

It is a self number, because there is not a number n which added to its sum of digits gives 221221121212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3315403 + ... + 3381469.

Almost surely, 2^221221121212 is an apocalyptic number.

It is an amenable number.

221221121212 is an abundant number, since it is smaller than the sum of its proper divisors (255314149188).

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

221221121212 is a wasteful number, since it uses less digits than its factorization.

221221121212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75290 (or 75288 counting only the distinct ones).

The product of its digits is 128, while the sum is 19.

Adding to 221221121212 its reverse (212121122122), we get a palindrome (433342243334).

The spelling of 221221121212 in words is "two hundred twenty-one billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred twelve".