505999 has 4 divisors (see below), whose sum is σ = 544936. Its totient is φ = 467064.

The previous prime is 505979. The next prime is 506047. The reversal of 505999 is 999505.

It is a happy number.

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

It is not a de Polignac number, because 505999 - 2⁷ = 505871 is a prime.

It is a Duffinian number.

505999 is a modest number, since divided by 999 gives 505 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (505919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19449 + ... + 19474.

It is an arithmetic number, because the mean of its divisors is an integer number (136234).

2⁵⁰⁵⁹⁹⁹ is an apocalyptic number.

505999 is a deficient number, since it is larger than the sum of its proper divisors (38937).

505999 is a wasteful number, since it uses less digits than its factorization.

505999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38936.

The product of its (nonzero) digits is 18225, while the sum is 37.

The square root of 505999 is about 711.3360668489. The cubic root of 505999 is about 79.6862187927.

The spelling of 505999 in words is "five hundred five thousand, nine hundred ninety-nine".