Search a number
BaseRepresentation
bin10001010001
31111221
4101101
513410
65041
73136
oct2121
91457
101105
11915
12781
13670
1458d
154da
hex451

1105 has 8 divisors (see below), whose sum is σ = 1512. Its totient is φ = 768.

The previous prime is 1103. The next prime is 1109. The reversal of 1105 is 5011.

1105 = T6 + T7 + ... + T18.

1105 = 232 + 242.

1105 is nontrivially palindromic in base 2 and base 4.

1105 is an esthetic number in base 8, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in 4 ways, for example, as 81 + 1024 = 9^2 + 32^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 2-Lehmer number, since φ(1105) divides (1105-1)2.

It is a cyclic number.

It is a Carmichael number.

It is not a de Polignac number, because 1105 - 21 = 1103 is a prime.

It is a Duffinian number.

1105 is an undulating number in base 8.

1105 is a lucky number.

It is a plaindrome in base 9 and base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1103) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57 + ... + 73.

It is an arithmetic number, because the mean of its divisors is an integer number (189).

It is the magic constant of a 13 × 13 magic square.

It is a Poulet number, since it divides 21104-1.

21105 is an apocalyptic number.

1105 is the 17-th decagonal number.

1105 is the 24-th centered square number.

It is an amenable number.

1105 is a deficient number, since it is larger than the sum of its proper divisors (407).

1105 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (1104) it forms an eRAP, since the sums of their prime factors are consecutive (34 and 35).

1105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35.

The product of its (nonzero) digits is 5, while the sum is 7.

The square root of 1105 is about 33.2415402772. The cubic root of 1105 is about 10.3384181241.

Adding to 1105 its reverse (5011), we get a palindrome (6116).

The spelling of 1105 in words is "one thousand, one hundred five".

Divisors: 1 5 13 17 65 85 221 1105