509131 has 4 divisors (see below), whose sum is σ = 581872. Its totient is φ = 436392.

The previous prime is 509123. The next prime is 509137. The reversal of 509131 is 131905.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 509131 - 2³ = 509123 is a prime.

It is a super-2 number, since 2×509131² = 518428750322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 509099 and 509108.

It is not an unprimeable number, because it can be changed into a prime (509137) 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 3 ways as a sum of consecutive naturals, for example, 36360 + ... + 36373.

It is an arithmetic number, because the mean of its divisors is an integer number (145468).

2⁵⁰⁹¹³¹ is an apocalyptic number.

509131 is a deficient number, since it is larger than the sum of its proper divisors (72741).

509131 is an equidigital number, since it uses as much as digits as its factorization.

509131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72740.

The product of its (nonzero) digits is 135, while the sum is 19.

The square root of 509131 is about 713.5341617610. The cubic root of 509131 is about 79.8502929389.

The spelling of 509131 in words is "five hundred nine thousand, one hundred thirty-one".