999878 has 16 divisors (see below), whose sum is σ = 1672704. Its totient is φ = 444360.

The previous prime is 999863. The next prime is 999883. The reversal of 999878 is 878999.

999878 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 999878.

It is an unprimeable number.

999878 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 551 + ... + 1517.

It is an arithmetic number, because the mean of its divisors is an integer number (104544).

2⁹⁹⁹⁸⁷⁸ is an apocalyptic number.

999878 is a deficient number, since it is larger than the sum of its proper divisors (672826).

999878 is a wasteful number, since it uses less digits than its factorization.

999878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1027.

The product of its digits is 326592, while the sum is 50.

The square root of 999878 is about 999.9389981394. The cubic root of 999878 is about 99.9959331679.

The spelling of 999878 in words is "nine hundred ninety-nine thousand, eight hundred seventy-eight".