509857 has 4 divisors (see below), whose sum is σ = 526336. Its totient is φ = 493380.

The previous prime is 509843. The next prime is 509863. The reversal of 509857 is 758905.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 509857 - 2¹¹ = 507809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (509837) 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, 8193 + ... + 8254.

It is an arithmetic number, because the mean of its divisors is an integer number (131584).

2⁵⁰⁹⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

509857 is a deficient number, since it is larger than the sum of its proper divisors (16479).

509857 is a wasteful number, since it uses less digits than its factorization.

509857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16478.

The product of its (nonzero) digits is 12600, while the sum is 34.

The square root of 509857 is about 714.0427158091. The cubic root of 509857 is about 79.8882293309. Note that the first 3 decimals are identical.

The spelling of 509857 in words is "five hundred nine thousand, eight hundred fifty-seven".