20121221211 has 32 divisors (see below), whose sum is σ = 33787353600.
Its totient is φ = 10366562304.
The previous prime is 20121221161. The next prime is 20121221249. The reversal of 20121221211 is 11212212102.
It is not a de Polignac number, because 20121221211 - 210 = 20121220187 is a prime.
It is not an unprimeable number, because it can be changed into a prime (20121221311) 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 31 ways as a sum of consecutive naturals, for example, 845286 + ... + 868763.
It is an arithmetic number, because the mean of its divisors is an integer number (1055854800).
Almost surely, 220121221211 is an apocalyptic number.
20121221211 is a gapful number since it is divisible by the number (21) formed by its first and last digit.
20121221211 is a deficient number, since it is larger than the sum of its proper divisors (13666132389).
20121221211 is a wasteful number, since it uses less digits than its factorization.
20121221211 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 1714115.
The product of its (nonzero) digits is 32, while the sum is 15.
Adding to 20121221211 its reverse (11212212102), we get a palindrome (31333433313).
The spelling of 20121221211 in words is "twenty billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred eleven".