240020509 has 2 divisors, whose sum is σ = 240020510. Its totient is φ = 240020508.

The previous prime is 240020489. The next prime is 240020533. The reversal of 240020509 is 905020042.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 230888025 + 9132484 = 15195^2 + 3022^2 .

It is a cyclic number.

It is not a de Polignac number, because 240020509 - 2²³ = 231631901 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 240020509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (240020009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 120010254 + 120010255.

It is an arithmetic number, because the mean of its divisors is an integer number (120010255).

Almost surely, 2^240020509 is an apocalyptic number.

It is an amenable number.

240020509 is a deficient number, since it is larger than the sum of its proper divisors (1).

240020509 is an equidigital number, since it uses as much as digits as its factorization.

240020509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 240020509 is about 15492.5952958179. The cubic root of 240020509 is about 621.4642024175.

The spelling of 240020509 in words is "two hundred forty million, twenty thousand, five hundred nine".