20121220211 has 4 divisors (see below), whose sum is σ = 20225475432. Its totient is φ = 20016964992.

The previous prime is 20121220187. The next prime is 20121220241. The reversal of 20121220211 is 11202212102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20121220211 - 2¹⁰ = 20121219187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20121220241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52127321 + ... + 52127706.

It is an arithmetic number, because the mean of its divisors is an integer number (5056368858).

Almost surely, 2^20121220211 is an apocalyptic number.

20121220211 is a deficient number, since it is larger than the sum of its proper divisors (104255221).

20121220211 is a wasteful number, since it uses less digits than its factorization.

20121220211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104255220.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20121220211 its reverse (11202212102), we get a palindrome (31323432313).

The spelling of 20121220211 in words is "twenty billion, one hundred twenty-one million, two hundred twenty thousand, two hundred eleven".