999438 has 32 divisors (see below), whose sum is σ = 2298240. Its totient is φ = 286560.

The previous prime is 999437. The next prime is 999451. The reversal of 999438 is 834999.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 999438.

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 999438.

It is not an unprimeable number, because it can be changed into a prime (999431) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 856 + ... + 1652.

It is an arithmetic number, because the mean of its divisors is an integer number (71820).

2⁹⁹⁹⁴³⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999438, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1149120).

999438 is an abundant number, since it is smaller than the sum of its proper divisors (1298802).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

999438 is a wasteful number, since it uses less digits than its factorization.

999438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 832.

The product of its digits is 69984, while the sum is 42.

The square root of 999438 is about 999.7189605084. The cubic root of 999438 is about 99.9812631562.

The spelling of 999438 in words is "nine hundred ninety-nine thousand, four hundred thirty-eight".