20101020111 has 24 divisors (see below), whose sum is σ = 29145669696. Its totient is φ = 13349609280.

The previous prime is 20101020109. The next prime is 20101020127. The reversal of 20101020111 is 11102010102.

It is a happy number.

It is not a de Polignac number, because 20101020111 - 2¹ = 20101020109 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 = 20101020093 and 20101020102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101120111) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2925466 + ... + 2932328.

It is an arithmetic number, because the mean of its divisors is an integer number (1214402904).

Almost surely, 2^20101020111 is an apocalyptic number.

20101020111 is a deficient number, since it is larger than the sum of its proper divisors (9044649585).

20101020111 is a wasteful number, since it uses less digits than its factorization.

20101020111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8063 (or 8060 counting only the distinct ones).

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

Adding to 20101020111 its reverse (11102010102), we get a palindrome (31203030213).

It can be divided in two parts, 2010 and 1020111, that added together give a square (1022121 = 1011²).

The spelling of 20101020111 in words is "twenty billion, one hundred one million, twenty thousand, one hundred eleven".