13644665 has 4 divisors (see below), whose sum is σ = 16373604. Its totient is φ = 10915728.

The previous prime is 13644647. The next prime is 13644667. The reversal of 13644665 is 56644631.

13644665 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 an emirpimes, since its reverse is a distinct semiprime: 56644631 = 43 ⋅1317317.

It can be written as a sum of positive squares in 2 ways, for example, as 8386816 + 5257849 = 2896^2 + 2293^2 .

It is a cyclic number.

It is not a de Polignac number, because 13644665 - 2¹⁴ = 13628281 is a prime.

It is a super-3 number, since 3×13644665³ (a number of 22 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13644667) 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, 1364462 + ... + 1364471.

It is an arithmetic number, because the mean of its divisors is an integer number (4093401).

Almost surely, 2^13644665 is an apocalyptic number.

It is an amenable number.

13644665 is a deficient number, since it is larger than the sum of its proper divisors (2728939).

13644665 is an equidigital number, since it uses as much as digits as its factorization.

13644665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2728938.

The product of its digits is 51840, while the sum is 35.

The square root of 13644665 is about 3693.8685683170. The cubic root of 13644665 is about 238.9576613085.

The spelling of 13644665 in words is "thirteen million, six hundred forty-four thousand, six hundred sixty-five".