221211021000000 has 392 divisors, whose sum is σ = 774635474539008. Its totient is φ = 55519616000000.

The previous prime is 221211020999987. The next prime is 221211021000037. The reversal of 221211021000000 is 120112122.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a self number, because there is not a number n which added to its sum of digits gives 221211021000000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 48831265 + ... + 53168735.

Almost surely, 2^{221211021000000} is an apocalyptic number.

221211021000000 is a gapful number since it is divisible by the number (20) 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 221211021000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (387317737269504).

221211021000000 is an abundant number, since it is smaller than the sum of its proper divisors (553424453539008).

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

221211021000000 is an frugal number, since it uses more digits than its factorization.

221211021000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4337533 (or 4337498 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 221211021000000 its reverse (120112122), we get a palindrome (221211141112122).

The spelling of 221211021000000 in words is "two hundred twenty-one trillion, two hundred eleven billion, twenty-one million", and thus it is an aban number.