999999869 has 8 divisors (see below), whose sum is σ = 1102156608. Its totient is φ = 899717760.

The previous prime is 999999797. The next prime is 999999883. The reversal of 999999869 is 968999999.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 999999869 - 2⁸ = 999999613 is a prime.

It is a super-2 number, since 2×999999869² = 1999999476000034322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 999999869.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999990869) 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 7 ways as a sum of consecutive naturals, for example, 467537 + ... + 469670.

It is an arithmetic number, because the mean of its divisors is an integer number (137769576).

Almost surely, 2^999999869 is an apocalyptic number.

It is an amenable number.

999999869 is a deficient number, since it is larger than the sum of its proper divisors (102156739).

999999869 is a wasteful number, since it uses less digits than its factorization.

999999869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 937315.

The product of its digits is 229582512, while the sum is 77.

The square root of 999999869 is about 31622.7745303919. The cubic root of 999999869 is about 999.9999563333. Note that the first 4 decimals are identical.

The spelling of 999999869 in words is "nine hundred ninety-nine million, nine hundred ninety-nine thousand, eight hundred sixty-nine".