20211221100212 has 36 divisors (see below), whose sum is σ = 38868196709580. Its totient is φ = 9183191721984.

The previous prime is 20211221100211. The next prime is 20211221100251. The reversal of 20211221100212 is 21200112211202.

It can be written as a sum of positive squares in 6 ways, for example, as 44421463696 + 20166799636516 = 210764^2 + 4490746^2 .

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211221100211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 301410533 + ... + 301477580.

Almost surely, 2^{20211221100212} is an apocalyptic number.

It is an amenable number.

20211221100212 is a deficient number, since it is larger than the sum of its proper divisors (18656975609368).

20211221100212 is a wasteful number, since it uses less digits than its factorization.

20211221100212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602888180 (or 602888161 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 20211221100212 its reverse (21200112211202), we get a palindrome (41411333311414).

The spelling of 20211221100212 in words is "twenty trillion, two hundred eleven billion, two hundred twenty-one million, one hundred thousand, two hundred twelve".