20221221220 has 12 divisors (see below), whose sum is σ = 42464564604. Its totient is φ = 8088488480.

The previous prime is 20221221187. The next prime is 20221221233. The reversal of 20221221220 is 2212212202.

It can be written as a sum of positive squares in 2 ways, for example, as 11332879936 + 8888341284 = 106456^2 + 94278^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20221221194 and 20221221203.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 505530511 + ... + 505530550.

It is an arithmetic number, because the mean of its divisors is an integer number (3538713717).

Almost surely, 2^20221221220 is an apocalyptic number.

20221221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20221221220 is an abundant number, since it is smaller than the sum of its proper divisors (22243343384).

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

20221221220 is a wasteful number, since it uses less digits than its factorization.

20221221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1011061070 (or 1011061068 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 20221221220 its reverse (2212212202), we get a palindrome (22433433422).

The spelling of 20221221220 in words is "twenty billion, two hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty".