999807 has 4 divisors (see below), whose sum is σ = 1333080. Its totient is φ = 666536.

The previous prime is 999773. The next prime is 999809. The reversal of 999807 is 708999.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 708999 = 3 ⋅236333.

It is a cyclic number.

It is not a de Polignac number, because 999807 - 2¹⁸ = 737663 is a prime.

It is a super-3 number, since 3×999807³ = 2998263335219432829, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999809) 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, 166632 + ... + 166637.

It is an arithmetic number, because the mean of its divisors is an integer number (333270).

2⁹⁹⁹⁸⁰⁷ is an apocalyptic number.

999807 is a deficient number, since it is larger than the sum of its proper divisors (333273).

999807 is a wasteful number, since it uses less digits than its factorization.

999807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333272.

The product of its (nonzero) digits is 40824, while the sum is 42.

The square root of 999807 is about 999.9034953434. The cubic root of 999807 is about 99.9935662527.

The spelling of 999807 in words is "nine hundred ninety-nine thousand, eight hundred seven".