20211221212120 has 32 divisors (see below), whose sum is σ = 45476186868000. Its totient is φ = 8084321526528.

The previous prime is 20211221212087. The next prime is 20211221212249. The reversal of 20211221212120 is 2121212211202.

It is a congruent number.

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, 3247164 + ... + 7139083.

It is an arithmetic number, because the mean of its divisors is an integer number (1421130839625).

Almost surely, 2^{20211221212120} is an apocalyptic number.

20211221212120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20211221212120 is an abundant number, since it is smaller than the sum of its proper divisors (25264965655880).

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

20211221212120 is a wasteful number, since it uses less digits than its factorization.

20211221212120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10434907 (or 10434903 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 20211221212120 its reverse (2121212211202), we get a palindrome (22332433423322).

The spelling of 20211221212120 in words is "twenty trillion, two hundred eleven billion, two hundred twenty-one million, two hundred twelve thousand, one hundred twenty".