20001220111 has 4 divisors (see below), whose sum is σ = 20029753224. Its totient is φ = 19972687000.

The previous prime is 20001220093. The next prime is 20001220147. The reversal of 20001220111 is 11102210002.

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 20001220111 - 2⁷ = 20001219983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001223111) 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, 14265505 + ... + 14266906.

It is an arithmetic number, because the mean of its divisors is an integer number (5007438306).

Almost surely, 2^20001220111 is an apocalyptic number.

20001220111 is a deficient number, since it is larger than the sum of its proper divisors (28533113).

20001220111 is an equidigital number, since it uses as much as digits as its factorization.

20001220111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28533112.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 20001220111 its reverse (11102210002), we get a palindrome (31103430113).

The spelling of 20001220111 in words is "twenty billion, one million, two hundred twenty thousand, one hundred eleven".