212100221220 has 96 divisors (see below), whose sum is σ = 615131919360. Its totient is φ = 54548590080.

The previous prime is 212100221209. The next prime is 212100221237. The reversal of 212100221220 is 22122001212.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 212100221220.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 350386 + ... + 739574.

It is an arithmetic number, because the mean of its divisors is an integer number (6407624160).

Almost surely, 2^212100221220 is an apocalyptic number.

212100221220 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 212100221220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (307565959680).

212100221220 is an abundant number, since it is smaller than the sum of its proper divisors (403031698140).

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

212100221220 is a wasteful number, since it uses less digits than its factorization.

212100221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389525 (or 389523 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 212100221220 its reverse (22122001212), we get a palindrome (234222222432).

The spelling of 212100221220 in words is "two hundred twelve billion, one hundred million, two hundred twenty-one thousand, two hundred twenty".