20221221020 has 288 divisors, whose sum is σ = 58345189056. Its totient is φ = 5786726400.

The previous prime is 20221220989. The next prime is 20221221049. The reversal of 20221221020 is 2012212202.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 20221220986 and 20221221004.

It is a congruent number.

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 95 ways as a sum of consecutive naturals, for example, 43863590 + ... + 43864050.

It is an arithmetic number, because the mean of its divisors is an integer number (202587462).

Almost surely, 2^20221221020 is an apocalyptic number.

20221221020 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 20221221020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29172594528).

20221221020 is an abundant number, since it is smaller than the sum of its proper divisors (38123968036).

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

20221221020 is a wasteful number, since it uses less digits than its factorization.

20221221020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 821 (or 812 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 20221221020 its reverse (2012212202), we get a palindrome (22233433222).

The spelling of 20221221020 in words is "twenty billion, two hundred twenty-one million, two hundred twenty-one thousand, twenty".