11111111111 has 4 divisors (see below), whose sum is σ = 11111646000. Its totient is φ = 11110576224.

The previous prime is 11111111059. The next prime is 11111111113.

11111111111 is nontrivially palindromic in base 10.

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-11111111111 is a prime.

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

11111111111 is a strobogrammatic number because it is the same when read upside-down.

It is a deceptive number, since it divides R_11111111110.

It is a Duffinian number.

11111111111 is a modest number, since divided by 111111 gives 11111 as remainder.

11111111111 is a nontrivial repdigit in base 10.

It is a plaindrome in base 10.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 11111111092 and 11111111101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11111111113) by changing a digit.

It is a nontrivial repunit in base 10.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 234971 + ... + 278268.

It is an arithmetic number, because the mean of its divisors is an integer number (2777911500).

Almost surely, 2^11111111111 is an apocalyptic number.

11111111111 is a deficient number, since it is larger than the sum of its proper divisors (534889).

11111111111 is an equidigital number, since it uses as much as digits as its factorization.

11111111111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 534888.

The product of its digits is 1, while the sum is 11.

Multiplying 11111111111 by its sum of digits (11), we get a palindrome (122222222221).

It can be divided in two parts, 111111111 and 11, that multiplied together give a palindrome (1222222221).

The spelling of 11111111111 in words is "eleven billion, one hundred eleven million, one hundred eleven thousand, one hundred eleven".