423528509 has 6 divisors (see below), whose sum is σ = 442743966. Its totient is φ = 405113720.

The previous prime is 423528503. The next prime is 423528517. The reversal of 423528509 is 905825324.

It can be written as a sum of positive squares in only one way, i.e., 415262884 + 8265625 = 20378^2 + 2875^2 .

It is not a de Polignac number, because 423528509 - 2²⁰ = 422479933 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (423528503) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 399782 + ... + 400839.

It is an arithmetic number, because the mean of its divisors is an integer number (73790661).

Almost surely, 2^423528509 is an apocalyptic number.

It is an amenable number.

423528509 is a deficient number, since it is larger than the sum of its proper divisors (19215457).

423528509 is an equidigital number, since it uses as much as digits as its factorization.

423528509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 800667 (or 800644 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 38.

The square root of 423528509 is about 20579.8082838495. The cubic root of 423528509 is about 750.9785798053.

The spelling of 423528509 in words is "four hundred twenty-three million, five hundred twenty-eight thousand, five hundred nine".