20201211311111 has 4 divisors (see below), whose sum is σ = 20360275967232. Its totient is φ = 20042146654992.

The previous prime is 20201211311063. The next prime is 20201211311117. The reversal of 20201211311111 is 11111311210202.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20201211311111 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20201211311111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20201211311117) 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, 79532327870 + ... + 79532328123.

It is an arithmetic number, because the mean of its divisors is an integer number (5090068991808).

Almost surely, 2^{20201211311111} is an apocalyptic number.

20201211311111 is a deficient number, since it is larger than the sum of its proper divisors (159064656121).

20201211311111 is a wasteful number, since it uses less digits than its factorization.

20201211311111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159064656120.

The product of its (nonzero) digits is 24, while the sum is 17.

Adding to 20201211311111 its reverse (11111311210202), we get a palindrome (31312522521313).

The spelling of 20201211311111 in words is "twenty trillion, two hundred one billion, two hundred eleven million, three hundred eleven thousand, one hundred eleven".