990042 has 16 divisors (see below), whose sum is σ = 1994592. Its totient is φ = 327600.

The previous prime is 990037. The next prime is 990043. The reversal of 990042 is 240099.

It is a junction number, because it is equal to n+sod(n) for n = 989994 and 990021.

It is not an unprimeable number, because it can be changed into a prime (990043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 417 + ... + 1467.

It is an arithmetic number, because the mean of its divisors is an integer number (124662).

2⁹⁹⁰⁰⁴² is an apocalyptic number.

990042 is an abundant number, since it is smaller than the sum of its proper divisors (1004550).

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

990042 is a wasteful number, since it uses less digits than its factorization.

990042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1213.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 990042 is about 995.0085426769. The cubic root of 990042 is about 99.6669587331. Note that the first 3 decimals are identical.

The spelling of 990042 in words is "nine hundred ninety thousand, forty-two".