20211221010220 has 24 divisors (see below), whose sum is σ = 42493089903264. Its totient is φ = 8075054921856.

The previous prime is 20211221010217. The next prime is 20211221010229. The reversal of 20211221010220 is 2201012211202.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20211221010194 and 20211221010203.

It is not an unprimeable number, because it can be changed into a prime (20211221010229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 589575072 + ... + 589609351.

It is an arithmetic number, because the mean of its divisors is an integer number (1770545412636).

Almost surely, 2^{20211221010220} is an apocalyptic number.

20211221010220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20211221010220 is an abundant number, since it is smaller than the sum of its proper divisors (22281868893044).

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

20211221010220 is a wasteful number, since it uses less digits than its factorization.

20211221010220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1179185289 (or 1179185287 counting only the distinct ones).

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

Adding to 20211221010220 its reverse (2201012211202), we get a palindrome (22412233221422).

The spelling of 20211221010220 in words is "twenty trillion, two hundred eleven billion, two hundred twenty-one million, ten thousand, two hundred twenty".