990000 has 150 divisors (see below), whose sum is σ = 3776916. Its totient is φ = 240000.

The previous prime is 989999. The next prime is 990001. The reversal of 990000 is 99.

990000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (989999) and next prime (990001).

It is a tau number, because it is divible by the number of its divisors (150).

It is a Harshad number since it is a multiple of its sum of digits (18).

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

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (990001) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 89995 + ... + 90005.

2⁹⁹⁰⁰⁰⁰ is an apocalyptic number.

990000 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 990000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1888458).

990000 is an abundant number, since it is smaller than the sum of its proper divisors (2786916).

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

990000 is a wasteful number, since it uses less digits than its factorization.

990000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45 (or 21 counting only the distinct ones).

The product of its (nonzero) digits is 81, while the sum is 18.

The square root of 990000 is about 994.9874371066. The cubic root of 990000 is about 99.6655493413.

Adding to 990000 its reverse (99), we get a palindrome (990099).

Multiplying 990000 by its reverse (99), we get a square (98010000 = 9900²).

990000 divided by its reverse (99) gives a 4-th power (10000 = 10⁴).

It can be divided in two parts, 9 and 90000, that multiplied together give a 4-th power (810000 = 30⁴).

The spelling of 990000 in words is "nine hundred ninety thousand".