13645 has 4 divisors (see below), whose sum is σ = 16380. Its totient is φ = 10912.

The previous prime is 13633. The next prime is 13649. The reversal of 13645 is 54631.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9801 + 3844 = 99^2 + 62^2 .

It is a cyclic number.

It is not a de Polignac number, because 13645 - 2⁵ = 13613 is a prime.

It is a super-3 number, since 3×13645³ = 7621524933375, which contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1360 + ... + 1369.

It is an arithmetic number, because the mean of its divisors is an integer number (4095).

2¹³⁶⁴⁵ is an apocalyptic number.

It is an amenable number.

13645 is a deficient number, since it is larger than the sum of its proper divisors (2735).

13645 is an equidigital number, since it uses as much as digits as its factorization.

13645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2734.

The product of its digits is 360, while the sum is 19.

The square root of 13645 is about 116.8118144710. The cubic root of 13645 is about 23.8959616900.

It can be divided in two parts, 1364 and 5, that added together give a square (1369 = 37²).

The spelling of 13645 in words is "thirteen thousand, six hundred forty-five".