990090 has 64 divisors (see below), whose sum is σ = 2793600. Its totient is φ = 248832.

The previous prime is 990053. The next prime is 990137. The reversal of 990090 is 90099.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is an unprimeable number.

990090 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 (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5034 + ... + 5226.

It is an arithmetic number, because the mean of its divisors is an integer number (43650).

2⁹⁹⁰⁰⁹⁰ is an apocalyptic number.

990090 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 990090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1396800).

990090 is an abundant number, since it is smaller than the sum of its proper divisors (1803510).

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

990090 is a wasteful number, since it uses less digits than its factorization.

990090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228 (or 222 counting only the distinct ones).

The product of its (nonzero) digits is 729, while the sum is 27.

The square root of 990090 is about 995.0326627805. The cubic root of 990090 is about 99.6685694179.

The spelling of 990090 in words is "nine hundred ninety thousand, ninety".