990438 has 16 divisors (see below), whose sum is σ = 1990656. Its totient is φ = 328520.

The previous prime is 990397. The next prime is 990463. The reversal of 990438 is 834099.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 990399 and 990408.

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 990438.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2083 + ... + 2513.

It is an arithmetic number, because the mean of its divisors is an integer number (124416).

2⁹⁹⁰⁴³⁸ is an apocalyptic number.

990438 is an abundant number, since it is smaller than the sum of its proper divisors (1000218).

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

990438 is a wasteful number, since it uses less digits than its factorization.

990438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 819.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 990438 is about 995.2075160488. The cubic root of 990438 is about 99.6802453259.

The spelling of 990438 in words is "nine hundred ninety thousand, four hundred thirty-eight".