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BaseRepresentation
bin100100010101101
3221112002
410202231
51043410
6222045
7105146
oct44255
927462
1018605
1112a84
12a925
138612
146acd
1557a5

18605 has 6 divisors (see below), whose sum is σ = 22698. Its totient is φ = 14640.

The previous prime is 18593. The next prime is 18617. The reversal of 18605 is 50681.

Multipling 18605 by its sum of digits (20), we get a square (372100 = 6102).

It is an interprime number because it is at equal distance from previous prime (18593) and next prime (18617).

It can be written as a sum of positive squares in 3 ways, for example, as 1444 + 17161 = 38^2 + 131^2 .

It is not a de Polignac number, because 18605 - 26 = 18541 is a prime.

It is a super-2 number, since 2×186052 = 692292050, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 14 and base 16.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 275 + ... + 335.

It is an arithmetic number, because the mean of its divisors is an integer number (3783).

218605 is an apocalyptic number.

It is an amenable number.

18605 is a deficient number, since it is larger than the sum of its proper divisors (4093).

18605 is an frugal number, since it uses more digits than its factorization.

18605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127 (or 66 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 18605 is about 136.4001466275. The cubic root of 18605 is about 26.4978044936.

The spelling of 18605 in words is "eighteen thousand, six hundred five".

Divisors: 1 5 61 305 3721 18605