999911 has 4 divisors (see below), whose sum is σ = 1090824. Its totient is φ = 909000.

The previous prime is 999907. The next prime is 999917. The reversal of 999911 is 119999.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 119999 = 11 ⋅10909.

It is a cyclic number.

It is not a de Polignac number, because 999911 - 2² = 999907 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

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 999911.

It is not an unprimeable number, because it can be changed into a prime (999917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45440 + ... + 45461.

It is an arithmetic number, because the mean of its divisors is an integer number (272706).

2⁹⁹⁹⁹¹¹ is an apocalyptic number.

999911 is a deficient number, since it is larger than the sum of its proper divisors (90913).

999911 is a wasteful number, since it uses less digits than its factorization.

999911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90912.

The product of its digits is 6561, while the sum is 38.

The square root of 999911 is about 999.9554990098. The cubic root of 999911 is about 99.9970332453.

It can be divided in two parts, 99 and 9911, that multiplied together give a palindrome (981189).

The spelling of 999911 in words is "nine hundred ninety-nine thousand, nine hundred eleven".