509091 has 8 divisors (see below), whose sum is σ = 740544. Its totient is φ = 308520.

The previous prime is 509087. The next prime is 509101. The reversal of 509091 is 190905.

It is a happy number.

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

It is not a de Polignac number, because 509091 - 2² = 509087 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

509091 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (509071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7681 + ... + 7746.

It is an arithmetic number, because the mean of its divisors is an integer number (92568).

2⁵⁰⁹⁰⁹¹ is an apocalyptic number.

509091 is a deficient number, since it is larger than the sum of its proper divisors (231453).

509091 is a wasteful number, since it uses less digits than its factorization.

509091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15441.

The product of its (nonzero) digits is 405, while the sum is 24.

The square root of 509091 is about 713.5061317186. The cubic root of 509091 is about 79.8482017316.

Adding to 509091 its reverse (190905), we get a palindrome (699996).

The spelling of 509091 in words is "five hundred nine thousand, ninety-one".