221122021212 has 144 divisors (see below), whose sum is σ = 574033824000. Its totient is φ = 71745550848.

The previous prime is 221122021201. The next prime is 221122021259. The reversal of 221122021212 is 212120221122.

It is a happy number.

221122021212 is a `hidden beast` number, since 2 + 211 + 220 + 21 + 212 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 148502964 + ... + 148504452.

It is an arithmetic number, because the mean of its divisors is an integer number (3986346000).

Almost surely, 2^221122021212 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 221122021212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (287016912000).

221122021212 is an abundant number, since it is smaller than the sum of its proper divisors (352911802788).

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

221122021212 is a wasteful number, since it uses less digits than its factorization.

221122021212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2200 (or 2195 counting only the distinct ones).

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

Adding to 221122021212 its reverse (212120221122), we get a palindrome (433242242334).

The spelling of 221122021212 in words is "two hundred twenty-one billion, one hundred twenty-two million, twenty-one thousand, two hundred twelve".