20021001121220 has 96 divisors (see below), whose sum is σ = 46862871390720. Its totient is φ = 7122313981440.

The previous prime is 20021001121213. The next prime is 20021001121229. The reversal of 20021001121220 is 2212110012002.

It is a junction number, because it is equal to n+sod(n) for n = 20021001121195 and 20021001121204.

It is not an unprimeable number, because it can be changed into a prime (20021001121229) 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 31 ways as a sum of consecutive naturals, for example, 23034782 + ... + 23888138.

It is an arithmetic number, because the mean of its divisors is an integer number (488154910320).

Almost surely, 2^{20021001121220} is an apocalyptic number.

20021001121220 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 20021001121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23431435695360).

20021001121220 is an abundant number, since it is smaller than the sum of its proper divisors (26841870269500).

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

20021001121220 is a wasteful number, since it uses less digits than its factorization.

20021001121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 855693 (or 855691 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20021001121220 its reverse (2212110012002), we get a palindrome (22233111133222).

The spelling of 20021001121220 in words is "twenty trillion, twenty-one billion, one million, one hundred twenty-one thousand, two hundred twenty".