999999867 has 4 divisors (see below), whose sum is σ = 1333333160. Its totient is φ = 666666576.

The previous prime is 999999797. The next prime is 999999883. The reversal of 999999867 is 768999999.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 999999867 - 2⁷ = 999999739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (999999067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166666642 + ... + 166666647.

It is an arithmetic number, because the mean of its divisors is an integer number (333333290).

Almost surely, 2^999999867 is an apocalyptic number.

999999867 is a deficient number, since it is larger than the sum of its proper divisors (333333293).

999999867 is a wasteful number, since it uses less digits than its factorization.

999999867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333333292.

The product of its digits is 178564176, while the sum is 75.

The square root of 999999867 is about 31622.7744987691. The cubic root of 999999867 is about 999.9999556667. Note that the first 4 decimals are identical.

The spelling of 999999867 in words is "nine hundred ninety-nine million, nine hundred ninety-nine thousand, eight hundred sixty-seven".