20311211111 has 4 divisors (see below), whose sum is σ = 20348343672. Its totient is φ = 20274078552.

The previous prime is 20311211083. The next prime is 20311211131. The reversal of 20311211111 is 11111211302.

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 20311211111 - 2¹⁴ = 20311194727 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 (20311211131) 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, 18565460 + ... + 18566553.

It is an arithmetic number, because the mean of its divisors is an integer number (5087085918).

Almost surely, 2^20311211111 is an apocalyptic number.

20311211111 is a deficient number, since it is larger than the sum of its proper divisors (37132561).

20311211111 is an equidigital number, since it uses as much as digits as its factorization.

20311211111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37132560.

The product of its (nonzero) digits is 12, while the sum is 14.

Adding to 20311211111 its reverse (11111211302), we get a palindrome (31422422413).

The spelling of 20311211111 in words is "twenty billion, three hundred eleven million, two hundred eleven thousand, one hundred eleven".