240409 has 4 divisors (see below), whose sum is σ = 258916. Its totient is φ = 221904.

The previous prime is 240379. The next prime is 240421. The reversal of 240409 is 904042.

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 64009 + 176400 = 253^2 + 420^2 .

It is a cyclic number.

It is not a de Polignac number, because 240409 - 2¹¹ = 238361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (240479) 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, 9234 + ... + 9259.

It is an arithmetic number, because the mean of its divisors is an integer number (64729).

2²⁴⁰⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

240409 is a deficient number, since it is larger than the sum of its proper divisors (18507).

240409 is a wasteful number, since it uses less digits than its factorization.

240409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18506.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 240409 is about 490.3152047408. The cubic root of 240409 is about 62.1799316985.

The spelling of 240409 in words is "two hundred forty thousand, four hundred nine".