5518409 has 4 divisors (see below), whose sum is σ = 5942916. Its totient is φ = 5093904.

The previous prime is 5518399. The next prime is 5518423. The reversal of 5518409 is 9048155.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9048155 = 5 ⋅1809631.

It can be written as a sum of positive squares in 2 ways, for example, as 990025 + 4528384 = 995^2 + 2128^2 .

It is a cyclic number.

It is not a de Polignac number, because 5518409 - 2²⁰ = 4469833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5518109) 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, 212234 + ... + 212259.

It is an arithmetic number, because the mean of its divisors is an integer number (1485729).

Almost surely, 2^5518409 is an apocalyptic number.

It is an amenable number.

5518409 is a deficient number, since it is larger than the sum of its proper divisors (424507).

5518409 is a wasteful number, since it uses less digits than its factorization.

5518409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424506.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 5518409 is about 2349.1294132082. The cubic root of 5518409 is about 176.7141373957.

The spelling of 5518409 in words is "five million, five hundred eighteen thousand, four hundred nine".