999000855 has 24 divisors (see below), whose sum is σ = 1736618832. Its totient is φ = 531256704.

The previous prime is 999000841. The next prime is 999000901. The reversal of 999000855 is 558000999.

It is not a de Polignac number, because 999000855 - 2¹¹ = 998998807 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 999000855.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16374 + ... + 47603.

It is an arithmetic number, because the mean of its divisors is an integer number (72359118).

Almost surely, 2^999000855 is an apocalyptic number.

999000855 is a deficient number, since it is larger than the sum of its proper divisors (737617977).

999000855 is a wasteful number, since it uses less digits than its factorization.

999000855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64335 (or 64332 counting only the distinct ones).

The product of its (nonzero) digits is 145800, while the sum is 45.

The square root of 999000855 is about 31606.9747840568. The cubic root of 999000855 is about 999.6668406839. Note that the first 3 decimals are identical.

The spelling of 999000855 in words is "nine hundred ninety-nine million, eight hundred fifty-five", and thus it is an aban number.