999005 has 32 divisors (see below), whose sum is σ = 1534464. Its totient is φ = 608256.

The previous prime is 998989. The next prime is 999007. The reversal of 999005 is 500999.

It is a cyclic number.

It is not a de Polignac number, because 999005 - 2⁴ = 998989 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999007) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13649 + ... + 13721.

It is an arithmetic number, because the mean of its divisors is an integer number (47952).

2⁹⁹⁹⁰⁰⁵ is an apocalyptic number.

It is an amenable number.

999005 is a deficient number, since it is larger than the sum of its proper divisors (535459).

999005 is a wasteful number, since it uses less digits than its factorization.

999005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125.

The product of its (nonzero) digits is 3645, while the sum is 32.

The square root of 999005 is about 999.5023761853. The cubic root of 999005 is about 99.9668223270.

It can be divided in two parts, 99900 and 5, that multiplied together give a triangular number (499500 = T₉₉₉).

The spelling of 999005 in words is "nine hundred ninety-nine thousand, five".