999409 has 8 divisors (see below), whose sum is σ = 1044992. Its totient is φ = 954720.

The previous prime is 999389. The next prime is 999431. The reversal of 999409 is 904999.

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 999409 - 2⁵ = 999377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (999499) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3037 + ... + 3349.

It is an arithmetic number, because the mean of its divisors is an integer number (130624).

2⁹⁹⁹⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

999409 is a deficient number, since it is larger than the sum of its proper divisors (45583).

999409 is a wasteful number, since it uses less digits than its factorization.

999409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447.

The product of its (nonzero) digits is 26244, while the sum is 40.

The square root of 999409 is about 999.7044563270. The cubic root of 999409 is about 99.9802961178.

The spelling of 999409 in words is "nine hundred ninety-nine thousand, four hundred nine".