1009999 has 4 divisors (see below), whose sum is σ = 1053936. Its totient is φ = 966064.

The previous prime is 1009997. The next prime is 1010003. The reversal of 1009999 is 9999001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9999001 = 71 ⋅140831.

It is a cyclic number.

It is not a de Polignac number, because 1009999 - 2¹ = 1009997 is a prime.

It is a Duffinian number.

1009999 is a modest number, since divided by 9999 gives 100 as remainder.

1009999 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1009991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21934 + ... + 21979.

It is an arithmetic number, because the mean of its divisors is an integer number (263484).

2^1009999 is an apocalyptic number.

1009999 is a deficient number, since it is larger than the sum of its proper divisors (43937).

1009999 is an equidigital number, since it uses as much as digits as its factorization.

1009999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43936.

The product of its (nonzero) digits is 6561, while the sum is 37.

The square root of 1009999 is about 1004.9870645934. The cubic root of 1009999 is about 100.3321952413.

The spelling of 1009999 in words is "one million, nine thousand, nine hundred ninety-nine".