990558 has 24 divisors (see below), whose sum is σ = 2169648. Its totient is φ = 326592.

The previous prime is 990547. The next prime is 990559. The reversal of 990558 is 855099.

It is a super-3 number, since 3×990558³ = 2915821836974463336, which contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990559) by changing a digit.

990558 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1791 + ... + 2277.

It is an arithmetic number, because the mean of its divisors is an integer number (90402).

2⁹⁹⁰⁵⁵⁸ is an apocalyptic number.

990558 is an abundant number, since it is smaller than the sum of its proper divisors (1179090).

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

990558 is a wasteful number, since it uses less digits than its factorization.

990558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608 (or 605 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 36.

The square root of 990558 is about 995.2678031565. The cubic root of 990558 is about 99.6842708669.

The spelling of 990558 in words is "nine hundred ninety thousand, five hundred fifty-eight".