240509 has 2 divisors, whose sum is σ = 240510. Its totient is φ = 240508.

The previous prime is 240503. The next prime is 240517. The reversal of 240509 is 905042.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 225625 + 14884 = 475^2 + 122^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-240509 is a prime.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (240503) 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 as a sum of consecutive naturals, namely, 120254 + 120255.

It is an arithmetic number, because the mean of its divisors is an integer number (120255).

2²⁴⁰⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

240509 is a deficient number, since it is larger than the sum of its proper divisors (1).

240509 is an equidigital number, since it uses as much as digits as its factorization.

240509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 240509 is about 490.4171693569. The cubic root of 240509 is about 62.1885519127.

It can be divided in two parts, 2 and 40509, that multiplied together give a palindrome (81018).

The spelling of 240509 in words is "two hundred forty thousand, five hundred nine".