999905 has 8 divisors (see below), whose sum is σ = 1238784. Its totient is φ = 774000.

The previous prime is 999883. The next prime is 999907. The reversal of 999905 is 509999.

999905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a de Polignac number, because none of the positive numbers 2^k-999905 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (999907) 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, 3071 + ... + 3380.

It is an arithmetic number, because the mean of its divisors is an integer number (154848).

2⁹⁹⁹⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

999905 is a deficient number, since it is larger than the sum of its proper divisors (238879).

999905 is a wasteful number, since it uses less digits than its factorization.

999905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6487.

The product of its (nonzero) digits is 32805, while the sum is 41.

The square root of 999905 is about 999.9524988718. The cubic root of 999905 is about 99.9968332331.

The spelling of 999905 in words is "nine hundred ninety-nine thousand, nine hundred five".