405505 has 4 divisors (see below), whose sum is σ = 486612. Its totient is φ = 324400.

The previous prime is 405499. The next prime is 405521. The reversal of 405505 is 505504.

It is a happy number.

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 226576 + 178929 = 476^2 + 423^2 .

It is not a de Polignac number, because 405505 - 2³ = 405497 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 (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40546 + ... + 40555.

It is an arithmetic number, because the mean of its divisors is an integer number (121653).

It is a Proth number, since it is equal to 99 ⋅ 2¹² + 1 and 99 < 2¹².

2⁴⁰⁵⁵⁰⁵ is an apocalyptic number.

It is an amenable number.

405505 is a deficient number, since it is larger than the sum of its proper divisors (81107).

405505 is an equidigital number, since it uses as much as digits as its factorization.

405505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81106.

The product of its (nonzero) digits is 500, while the sum is 19.

The square root of 405505 is about 636.7927449335. The cubic root of 405505 is about 74.0171009905.

Subtracting 405505 from its reverse (505504), we obtain a palindrome (99999).

The spelling of 405505 in words is "four hundred five thousand, five hundred five".