221221102212 has 288 divisors, whose sum is σ = 643936204800. Its totient is φ = 65613240000.

The previous prime is 221221102183. The next prime is 221221102237. The reversal of 221221102212 is 212201122122.

It is a happy number.

221221102212 is a `hidden beast` number, since 221 + 221 + 1 + 0 + 221 + 2 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 140101239 + ... + 140102817.

It is an arithmetic number, because the mean of its divisors is an integer number (2235889600).

Almost surely, 2^221221102212 is an apocalyptic number.

221221102212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221221102212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (321968102400).

221221102212 is an abundant number, since it is smaller than the sum of its proper divisors (422715102588).

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

221221102212 is a wasteful number, since it uses less digits than its factorization.

221221102212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1836 (or 1817 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 221221102212 its reverse (212201122122), we get a palindrome (433422224334).

The spelling of 221221102212 in words is "two hundred twenty-one billion, two hundred twenty-one million, one hundred two thousand, two hundred twelve".