20011111111 has 12 divisors (see below), whose sum is σ = 21751851352. Its totient is φ = 18395975808.

The previous prime is 20011111051. The next prime is 20011111129. The reversal of 20011111111 is 11111111002.

It is not a de Polignac number, because 20011111111 - 2²⁷ = 19876893383 is a prime.

It is a Duffinian number.

20011111111 is a modest number, since divided by 111111 gives 20011 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011111151) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 792720 + ... + 817573.

Almost surely, 2^20011111111 is an apocalyptic number.

20011111111 is a deficient number, since it is larger than the sum of its proper divisors (1740740241).

20011111111 is a wasteful number, since it uses less digits than its factorization.

20011111111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1610370 (or 1610353 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 10.

Adding to 20011111111 its reverse (11111111002), we get a palindrome (31122222113).

The spelling of 20011111111 in words is "twenty billion, eleven million, one hundred eleven thousand, one hundred eleven".