20021100021220 has 192 divisors, whose sum is σ = 44898739200000. Its totient is φ = 7477859450880.

The previous prime is 20021100021203. The next prime is 20021100021257. The reversal of 20021100021220 is 2212000112002.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20021100021220.

It is an unprimeable number.

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, 11633409960 + ... + 11633411680.

It is an arithmetic number, because the mean of its divisors is an integer number (233847600000).

Almost surely, 2^{20021100021220} is an apocalyptic number.

20021100021220 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 20021100021220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22449369600000).

20021100021220 is an abundant number, since it is smaller than the sum of its proper divisors (24877639178780).

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

20021100021220 is a wasteful number, since it uses less digits than its factorization.

20021100021220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3318 (or 3316 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 20021100021220 its reverse (2212000112002), we get a palindrome (22233100133222).

The spelling of 20021100021220 in words is "twenty trillion, twenty-one billion, one hundred million, twenty-one thousand, two hundred twenty".