999819 has 6 divisors (see below), whose sum is σ = 1444196. Its totient is φ = 666540.

The previous prime is 999809. The next prime is 999853. The reversal of 999819 is 918999.

999819 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 999819 - 2⁸ = 999563 is a prime.

It is a super-2 number, since 2×999819² = 1999276065522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (999809) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 55537 + ... + 55554.

2⁹⁹⁹⁸¹⁹ is an apocalyptic number.

999819 is a deficient number, since it is larger than the sum of its proper divisors (444377).

999819 is a wasteful number, since it uses less digits than its factorization.

999819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111097 (or 111094 counting only the distinct ones).

The product of its digits is 52488, while the sum is 45.

The square root of 999819 is about 999.9094959045. The cubic root of 999819 is about 99.9939663026.

The spelling of 999819 in words is "nine hundred ninety-nine thousand, eight hundred nineteen".