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18785 = 513172
BaseRepresentation
bin100100101100001
3221202202
410211201
51100120
6222545
7105524
oct44541
927682
1018785
1113128
12aa55
138720
146bbb
155875
hex4961

18785 has 12 divisors (see below), whose sum is σ = 25788. Its totient is φ = 13056.

The previous prime is 18773. The next prime is 18787. The reversal of 18785 is 58781.

It is a happy number.

18785 is nontrivially palindromic in base 4.

It can be written as a sum of positive squares in 6 ways, for example, as 16 + 18769 = 4^2 + 137^2 .

It is not a de Polignac number, because 18785 - 210 = 17761 is a prime.

It is a Leyland number of the form 74 + 47.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

Its product of digits (2240) is a multiple of the sum of its prime divisors (35).

It is a Curzon number.

It is a plaindrome in base 14.

It is a nialpdrome in base 12 and base 13.

It is a zygodrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18787) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1097 + ... + 1113.

It is an arithmetic number, because the mean of its divisors is an integer number (2149).

218785 is an apocalyptic number.

It is an amenable number.

18785 is a deficient number, since it is larger than the sum of its proper divisors (7003).

18785 is a wasteful number, since it uses less digits than its factorization.

18785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52 (or 35 counting only the distinct ones).

The product of its digits is 2240, while the sum is 29.

The square root of 18785 is about 137.0583817211. The cubic root of 18785 is about 26.5829841991.

Adding to 18785 its product of digits (2240), we get a square (21025 = 1452).

It can be divided in two parts, 187 and 85, that added together give a palindrome (272).

The spelling of 18785 in words is "eighteen thousand, seven hundred eighty-five".

Divisors: 1 5 13 17 65 85 221 289 1105 1445 3757 18785