12221222121000 has 192 divisors, whose sum is σ = 41322256045200. Its totient is φ = 3257846592000.

The previous prime is 12221222120959. The next prime is 12221222121071. The reversal of 12221222121000 is 12122212221.

It is a happy number.

12221222121000 is a `hidden beast` number, since 1 + 22 + 212 + 221 + 210 + 0 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 108358155684 + 12112863965316 = 329178^2 + 3480354^2 .

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

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, 25511686 + ... + 25986314.

Almost surely, 2^{12221222121000} is an apocalyptic number.

12221222121000 is a gapful number since it is divisible by the number (10) 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 12221222121000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20661128022600).

12221222121000 is an abundant number, since it is smaller than the sum of its proper divisors (29101033924200).

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

12221222121000 is a wasteful number, since it uses less digits than its factorization.

12221222121000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477517 (or 477500 counting only the distinct ones).

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

Adding to 12221222121000 its reverse (12122212221), we get a palindrome (12233344333221).

The spelling of 12221222121000 in words is "twelve trillion, two hundred twenty-one billion, two hundred twenty-two million, one hundred twenty-one thousand".