53665 has 4 divisors (see below), whose sum is σ = 64404. Its totient is φ = 42928.

The previous prime is 53657. The next prime is 53681. The reversal of 53665 is 56635.

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 10816 + 42849 = 104^2 + 207^2 .

It is a cyclic number.

It is not a de Polignac number, because 53665 - 2³ = 53657 is a prime.

It is a Duffinian 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 3 ways as a sum of consecutive naturals, for example, 5362 + ... + 5371.

It is an arithmetic number, because the mean of its divisors is an integer number (16101).

2⁵³⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

53665 is a deficient number, since it is larger than the sum of its proper divisors (10739).

53665 is a wasteful number, since it uses less digits than its factorization.

53665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10738.

The product of its digits is 2700, while the sum is 25.

The square root of 53665 is about 231.6570741419. The cubic root of 53665 is about 37.7193075378.

Adding to 53665 its product of digits (2700), we get a palindrome (56365).

It can be divided in two parts, 53 and 665, that multiplied together give a triangular number (35245 = T₂₆₅).

The spelling of 53665 in words is "fifty-three thousand, six hundred sixty-five".