21220120200 has 144 divisors (see below), whose sum is σ = 66459295440. Its totient is φ = 5601056000.

The previous prime is 21220120199. The next prime is 21220120219. The reversal of 21220120200 is 202102212.

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

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 6118867 + ... + 6122333.

It is an arithmetic number, because the mean of its divisors is an integer number (461522885).

Almost surely, 2^21220120200 is an apocalyptic number.

21220120200 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 21220120200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33229647720).

21220120200 is an abundant number, since it is smaller than the sum of its proper divisors (45239175240).

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

21220120200 is a wasteful number, since it uses less digits than its factorization.

21220120200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3688 (or 3578 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 21220120200 its reverse (202102212), we get a palindrome (21422222412).

The spelling of 21220120200 in words is "twenty-one billion, two hundred twenty million, one hundred twenty thousand, two hundred".