1213212221000 has 256 divisors, whose sum is σ = 3114218016000. Its totient is φ = 439640371200.

The previous prime is 1213212220939. The next prime is 1213212221003. The reversal of 1213212221000 is 1222123121.

It is a self number, because there is not a number n which added to its sum of digits gives 1213212221000.

It is not an unprimeable number, because it can be changed into a prime (1213212221003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 749358191 + ... + 749359809.

It is an arithmetic number, because the mean of its divisors is an integer number (12164914125).

Almost surely, 2^{1213212221000} is an apocalyptic number.

1213212221000 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 1213212221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1557109008000).

1213212221000 is an abundant number, since it is smaller than the sum of its proper divisors (1901005795000).

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

1213212221000 is a wasteful number, since it uses less digits than its factorization.

1213212221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2689 (or 2675 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 1213212221000 its reverse (1222123121), we get a palindrome (1214434344121).

The spelling of 1213212221000 in words is "one trillion, two hundred thirteen billion, two hundred twelve million, two hundred twenty-one thousand".