20201221210020 has 48 divisors (see below), whose sum is σ = 57490688568768. Its totient is φ = 5298680972160.

The previous prime is 20201221209991. The next prime is 20201221210021. The reversal of 20201221210020 is 2001212210202.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (20201221210021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2759726014 + ... + 2759733333.

It is an arithmetic number, because the mean of its divisors is an integer number (1197722678516).

Almost surely, 2^{20201221210020} is an apocalyptic number.

20201221210020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20201221210020 is an abundant number, since it is smaller than the sum of its proper divisors (37289467358748).

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

20201221210020 is a wasteful number, since it uses less digits than its factorization.

20201221210020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5519459420 (or 5519459418 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 20201221210020 its reverse (2001212210202), we get a palindrome (22202433420222).

The spelling of 20201221210020 in words is "twenty trillion, two hundred one billion, two hundred twenty-one million, two hundred ten thousand, twenty".