20001121221220 has 24 divisors (see below), whose sum is σ = 43828543894464. Its totient is φ = 7652602901856.

The previous prime is 20001121221181. The next prime is 20001121221241. The reversal of 20001121221220 is 2212212110002.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20001121221194 and 20001121221203.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21740348694 + ... + 21740349613.

It is an arithmetic number, because the mean of its divisors is an integer number (1826189328936).

Almost surely, 2^{20001121221220} is an apocalyptic number.

20001121221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20001121221220 is an abundant number, since it is smaller than the sum of its proper divisors (23827422673244).

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

20001121221220 is a wasteful number, since it uses less digits than its factorization.

20001121221220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43480698339 (or 43480698337 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 20001121221220 its reverse (2212212110002), we get a palindrome (22213333331222).

The spelling of 20001121221220 in words is "twenty trillion, one billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty".