43665 has 16 divisors (see below), whose sum is σ = 72576. Its totient is φ = 22400.

The previous prime is 43661. The next prime is 43669. The reversal of 43665 is 56634.

It is an interprime number because it is at equal distance from previous prime (43661) and next prime (43669).

It is not a de Polignac number, because 43665 - 2² = 43661 is a prime.

Its product of digits (2160) is a multiple of the sum of its prime divisors (120).

It is a nialpdrome in base 16.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 43665.

It is not an unprimeable number, because it can be changed into a prime (43661) 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 15 ways as a sum of consecutive naturals, for example, 580 + ... + 650.

It is an arithmetic number, because the mean of its divisors is an integer number (4536).

2⁴³⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

43665 is a deficient number, since it is larger than the sum of its proper divisors (28911).

43665 is a wasteful number, since it uses less digits than its factorization.

43665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120.

The product of its digits is 2160, while the sum is 24.

The square root of 43665 is about 208.9617189822. The cubic root of 43665 is about 35.2136590413.

It can be divided in two parts, 4366 and 5, that added together give a triangular number (4371 = T₉₃).

The spelling of 43665 in words is "forty-three thousand, six hundred sixty-five".