20121111211 has 4 divisors (see below), whose sum is σ = 20129536000. Its totient is φ = 20112686424.

The previous prime is 20121111191. The next prime is 20121111221. The reversal of 20121111211 is 11211112102.

It is a happy number.

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 20121111211 - 2¹¹ = 20121109163 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20121111191 and 20121111200.

It is not an unprimeable number, because it can be changed into a prime (20121111221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4208811 + ... + 4213588.

It is an arithmetic number, because the mean of its divisors is an integer number (5032384000).

Almost surely, 2^20121111211 is an apocalyptic number.

20121111211 is a deficient number, since it is larger than the sum of its proper divisors (8424789).

20121111211 is an equidigital number, since it uses as much as digits as its factorization.

20121111211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8424788.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 20121111211 its reverse (11211112102), we get a palindrome (31332223313).

The spelling of 20121111211 in words is "twenty billion, one hundred twenty-one million, one hundred eleven thousand, two hundred eleven".