20011020111 has 28 divisors (see below), whose sum is σ = 30072889440. Its totient is φ = 13309518240.

The previous prime is 20011020109. The next prime is 20011020137. The reversal of 20011020111 is 11102011002.

It is a happy number.

It is not a de Polignac number, because 20011020111 - 2¹ = 20011020109 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 20011020093 and 20011020102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011020151) 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 27 ways as a sum of consecutive naturals, for example, 282355 + ... + 346043.

Almost surely, 2^20011020111 is an apocalyptic number.

20011020111 is a deficient number, since it is larger than the sum of its proper divisors (10061869329).

20011020111 is an frugal number, since it uses more digits than its factorization.

20011020111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64138 (or 64123 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 20011020111 its reverse (11102011002), we get a palindrome (31113031113).

The spelling of 20011020111 in words is "twenty billion, eleven million, twenty thousand, one hundred eleven".