240405409 has 4 divisors (see below), whose sum is σ = 240806020. Its totient is φ = 240004800.

The previous prime is 240405401. The next prime is 240405419. The reversal of 240405409 is 904504042.

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 216001809 + 24403600 = 14697^2 + 4940^2 .

It is a cyclic number.

It is not a de Polignac number, because 240405409 - 2³ = 240405401 is a prime.

It is a Duffinian number.

240405409 is a modest number, since divided by 5409 gives 2404 as remainder.

It is not an unprimeable number, because it can be changed into a prime (240405401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199404 + ... + 200605.

It is an arithmetic number, because the mean of its divisors is an integer number (60201505).

Almost surely, 2^240405409 is an apocalyptic number.

It is an amenable number.

240405409 is a deficient number, since it is larger than the sum of its proper divisors (400611).

240405409 is an equidigital number, since it uses as much as digits as its factorization.

240405409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400610.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 240405409 is about 15505.0123830973. The cubic root of 240405409 is about 621.7962210216.

The spelling of 240405409 in words is "two hundred forty million, four hundred five thousand, four hundred nine".