999919 has 4 divisors (see below), whose sum is σ = 1001920. Its totient is φ = 997920.

The previous prime is 999917. The next prime is 999931. The reversal of 999919 is 919999.

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

It is a cyclic number.

It is not a de Polignac number, because 999919 - 2¹ = 999917 is a prime.

It is a super-2 number, since 2×999919² = 1999676013122, which contains 22 as substring.

It is a Duffinian number.

999919 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999917) 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, 487 + ... + 1495.

It is an arithmetic number, because the mean of its divisors is an integer number (250480).

2⁹⁹⁹⁹¹⁹ is an apocalyptic number.

999919 is a deficient number, since it is larger than the sum of its proper divisors (2001).

999919 is a wasteful number, since it uses less digits than its factorization.

999919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2000.

The product of its digits is 59049, while the sum is 46.

The square root of 999919 is about 999.9594991798. The cubic root of 999919 is about 99.9972999271.

It can be divided in two parts, 99991 and 9, that added together give a 5-th power (100000 = 10⁵).

The spelling of 999919 in words is "nine hundred ninety-nine thousand, nine hundred nineteen".