990505 has 16 divisors (see below), whose sum is σ = 1292544. Its totient is φ = 725760.

The previous prime is 990503. The next prime is 990511. The reversal of 990505 is 505099.

It is not a de Polignac number, because 990505 - 2¹ = 990503 is a prime.

It is a super-2 number, since 2×990505² = 1962200310050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (990503) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 3520 + ... + 3790.

It is an arithmetic number, because the mean of its divisors is an integer number (80784).

2⁹⁹⁰⁵⁰⁵ is an apocalyptic number.

It is an amenable number.

990505 is a deficient number, since it is larger than the sum of its proper divisors (302039).

990505 is a wasteful number, since it uses less digits than its factorization.

990505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336.

The product of its (nonzero) digits is 2025, while the sum is 28.

The square root of 990505 is about 995.2411768009. The cubic root of 990505 is about 99.6824929597.

The spelling of 990505 in words is "nine hundred ninety thousand, five hundred five".