55409 has 4 divisors (see below), whose sum is σ = 56304. Its totient is φ = 54516.

The previous prime is 55399. The next prime is 55411. The reversal of 55409 is 90455.

55409 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55409 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (55439) 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, 347 + ... + 480.

It is an arithmetic number, because the mean of its divisors is an integer number (14076).

2⁵⁵⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

55409 is a deficient number, since it is larger than the sum of its proper divisors (895).

55409 is an equidigital number, since it uses as much as digits as its factorization.

55409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 894.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 55409 is about 235.3911638104. The cubic root of 55409 is about 38.1235590246.

It can be divided in two parts, 55 and 409, that added together give a palindrome (464).

The spelling of 55409 in words is "fifty-five thousand, four hundred nine".