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13609 = 31439

13609 has 4 divisors (see below), whose sum is σ = 14080. Its totient is φ = 13140.

The previous prime is 13597. The next prime is 13613. The reversal of 13609 is 90631.

13609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 13609 - 25 = 13577 is a prime.

It is an Ulam number.

It is a Duffinian number.

13609 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (13619) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 189 + ... + 250.

It is an arithmetic number, because the mean of its divisors is an integer number (3520).

213609 is an apocalyptic number.

It is an amenable number.

13609 is a deficient number, since it is larger than the sum of its proper divisors (471).

13609 is an equidigital number, since it uses as much as digits as its factorization.

13609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 470.

The product of its (nonzero) digits is 162, while the sum is 19.

The square root of 13609 is about 116.6576186968. The cubic root of 13609 is about 23.8749280445.

It can be divided in two parts, 1360 and 9, that added together give a square (1369 = 372).

The spelling of 13609 in words is "thirteen thousand, six hundred nine".

Divisors: 1 31 439 13609