420509 has 8 divisors (see below), whose sum is σ = 449280. Its totient is φ = 392656.

The previous prime is 420503. The next prime is 420521. The reversal of 420509 is 905024.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 420509 - 2⁸ = 420253 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 (420503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 887 + ... + 1275.

It is an arithmetic number, because the mean of its divisors is an integer number (56160).

2⁴²⁰⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

420509 is a deficient number, since it is larger than the sum of its proper divisors (28771).

420509 is a wasteful number, since it uses less digits than its factorization.

420509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459.

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

The square root of 420509 is about 648.4666529591. The cubic root of 420509 is about 74.9189643263.

It can be divided in two parts, 420 and 509, that added together give a palindrome (929).

The spelling of 420509 in words is "four hundred twenty thousand, five hundred nine".