990687 has 4 divisors (see below), whose sum is σ = 1320920. Its totient is φ = 660456.

The previous prime is 990673. The next prime is 990707. The reversal of 990687 is 786099.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 990687 - 2⁷ = 990559 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 165112 + ... + 165117.

It is an arithmetic number, because the mean of its divisors is an integer number (330230).

2⁹⁹⁰⁶⁸⁷ is an apocalyptic number.

990687 is a deficient number, since it is larger than the sum of its proper divisors (330233).

990687 is a wasteful number, since it uses less digits than its factorization.

990687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330232.

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 990687 is about 995.3326077247. The cubic root of 990687 is about 99.6885979609.

The spelling of 990687 in words is "nine hundred ninety thousand, six hundred eighty-seven".