1111 has 4 divisors (see below), whose sum is σ = 1224. Its totient is φ = 1000.

The previous prime is 1109. The next prime is 1117.

It can be divided in two parts, 11 and 11, that added together give a palindrome (22).

1111 = 11^{2} + 12^{2} + ... + 16^{2}.

1111 is nontrivially palindromic in base 10, base 12, base 13 and base 14.

1111 is an esthetic number in base 12 and base 13, because in such bases its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes.

It is a 3-Lehmer number, since φ(1111) divides (1111-1)^{3}.

It is a cyclic number.

It is not a de Polignac number, because 1111 - 2^{1} = 1109 is a prime.

It is a Smith number, since the sum of its digits (4) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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.

1111 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

1111 is an undulating number in base 12, base 13 and base 14.

1111 is a modest number, since divided by 111 gives 1 as remainder.

1111 is a nontrivial repdigit in base 10.

It is a plaindrome in base 10 and base 16.

It is a nialpdrome in base 10 and base 11.

It is a zygodrome in base 10.

It is a self number, because there is not a number *n* which added to its sum of digits gives 1111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1117) 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, 40 + ... + 61.

It is an arithmetic number, because the mean of its divisors is an integer number (306).

1111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1111 is a deficient number, since it is larger than the sum of its proper divisors (113).

1111 is a wasteful number, since it uses less digits than its factorization.

1111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112.

The product of its digits is 1, while the sum is 4.

The square root of 1111 is about 33.3316666250. The cubic root of 1111 is about 10.3570964269.

The spelling of 1111 in words is "one thousand, one hundred eleven", and thus it is an iban number.

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