509440 has 40 divisors (see below), whose sum is σ = 1227600. Its totient is φ = 202752.

The previous prime is 509429. The next prime is 509441. The reversal of 509440 is 44905.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×509440² = 519058227200, which contains 22 as substring.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (509441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2461 + ... + 2659.

It is an arithmetic number, because the mean of its divisors is an integer number (30690).

2⁵⁰⁹⁴⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 509440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (613800).

509440 is an abundant number, since it is smaller than the sum of its proper divisors (718160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

509440 is an equidigital number, since it uses as much as digits as its factorization.

509440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222 (or 206 counting only the distinct ones).

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

The square root of 509440 is about 713.7506567423. The cubic root of 509440 is about 79.8664438251.

It can be divided in two parts, 509 and 440, that added together give a palindrome (949).

The spelling of 509440 in words is "five hundred nine thousand, four hundred forty".