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BaseRepresentation
bin10010000011
31120210
4102003
514110
65203
73240
oct2203
91523
101155
11960
12803
136ab
145c7
15520
hex483

1155 has 16 divisors (see below), whose sum is σ = 2304. Its totient is φ = 480.

The previous prime is 1153. The next prime is 1163. The reversal of 1155 is 5511.

Adding to 1155 its reverse (5511), we get a palindrome (6666).

Subtracting 1155 from its reverse (5511), we obtain a square (4356 = 662).

It can be divided in two parts, 115 and 5, that multiplied together give a palindrome (575).

It is a Cunningham number, because it is equal to 342-1.

It is not a de Polignac number, because 1155 - 21 = 1153 is a prime.

It is a nude number because it is divisible by every one of its digits.

It is an Ulam number.

1155 is a lucky number.

It is a plaindrome in base 10 and base 13.

It is a nialpdrome in base 11 and base 15.

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 1155.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 100 + ... + 110.

It is an arithmetic number, because the mean of its divisors is an integer number (144).

21155 is an apocalyptic number.

1155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1155 is a deficient number, since it is larger than the sum of its proper divisors (1149).

1155 is a wasteful number, since it uses less digits than its factorization.

1155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26.

The product of its digits is 25, while the sum is 12.

The square root of 1155 is about 33.9852909359. The cubic root of 1155 is about 10.4920574856.

The spelling of 1155 in words is "one thousand, one hundred fifty-five".

Divisors: 1 3 5 7 11 15 21 33 35 55 77 105 165 231 385 1155