53809 has 4 divisors (see below), whose sum is σ = 61504. Its totient is φ = 46116.

The previous prime is 53791. The next prime is 53813. The reversal of 53809 is 90835.

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 not a de Polignac number, because 53809 - 2⁵ = 53777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (53819) 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, 3837 + ... + 3850.

It is an arithmetic number, because the mean of its divisors is an integer number (15376).

2⁵³⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

53809 is a deficient number, since it is larger than the sum of its proper divisors (7695).

53809 is an equidigital number, since it uses as much as digits as its factorization.

53809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7694.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 53809 is about 231.9676701612. The cubic root of 53809 is about 37.7530149778.

The spelling of 53809 in words is "fifty-three thousand, eight hundred nine".