20011111111111 has 24 divisors (see below), whose sum is σ = 21606901265664. Its totient is φ = 18522031499280.

The previous prime is 20011111111039. The next prime is 20011111111213. The reversal of 20011111111111 is 11111111111002.

It is not a de Polignac number, because 20011111111111 - 2¹¹ = 20011111109063 is a prime.

It is a Duffinian number.

20011111111111 is a modest number, since divided by 11111111 gives 200111 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 20011111111091 and 20011111111100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011111141111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8655396 + ... + 10720918.

It is an arithmetic number, because the mean of its divisors is an integer number (900287552736).

Almost surely, 2^{20011111111111} is an apocalyptic number.

20011111111111 is a deficient number, since it is larger than the sum of its proper divisors (1595790154553).

20011111111111 is a wasteful number, since it uses less digits than its factorization.

20011111111111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2066179 (or 2066160 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 13.

Adding to 20011111111111 its reverse (11111111111002), we get a palindrome (31122222222113).

The spelling of 20011111111111 in words is "twenty trillion, eleven billion, one hundred eleven million, one hundred eleven thousand, one hundred eleven".