20201221201211 has 16 divisors (see below), whose sum is σ = 21443406734880. Its totient is φ = 18965049630720.

The previous prime is 20201221201121. The next prime is 20201221201219. The reversal of 20201221201211 is 11210212210202.

It is a cyclic number.

It is not a de Polignac number, because 20201221201211 - 2¹⁰ = 20201221200187 is a prime.

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

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20201221201211.

It is not an unprimeable number, because it can be changed into a prime (20201221201219) 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, 23198000 + ... + 24053058.

It is an arithmetic number, because the mean of its divisors is an integer number (1340212920930).

Almost surely, 2^{20201221201211} is an apocalyptic number.

20201221201211 is a deficient number, since it is larger than the sum of its proper divisors (1242185533669).

20201221201211 is a wasteful number, since it uses less digits than its factorization.

20201221201211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 858574.

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

Adding to 20201221201211 its reverse (11210212210202), we get a palindrome (31411433411413).

The spelling of 20201221201211 in words is "twenty trillion, two hundred one billion, two hundred twenty-one million, two hundred one thousand, two hundred eleven".