509404 has 36 divisors (see below), whose sum is σ = 1091664. Its totient is φ = 206976.

The previous prime is 509393. The next prime is 509413. The reversal of 509404 is 404905.

509404 = T₁₁₉ + T₁₂₀ + ... + T₁₆₇.

It is a nialpdrome in base 7.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4452 + ... + 4564.

It is an arithmetic number, because the mean of its divisors is an integer number (30324).

2⁵⁰⁹⁴⁰⁴ 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 509404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (545832).

509404 is an abundant number, since it is smaller than the sum of its proper divisors (582260).

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

509404 is a wasteful number, since it uses less digits than its factorization.

509404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154 (or 145 counting only the distinct ones).

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

The square root of 509404 is about 713.7254374057. The cubic root of 509404 is about 79.8645625046.

The spelling of 509404 in words is "five hundred nine thousand, four hundred four".