990689 has 8 divisors (see below), whose sum is σ = 1138368. Its totient is φ = 844560.

The previous prime is 990673. The next prime is 990707. The reversal of 990689 is 986099.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 990689 - 2⁴ = 990673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (990289) 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, 1919 + ... + 2379.

It is an arithmetic number, because the mean of its divisors is an integer number (142296).

2⁹⁹⁰⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

990689 is a deficient number, since it is larger than the sum of its proper divisors (147679).

990689 is a wasteful number, since it uses less digits than its factorization.

990689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 775.

The product of its (nonzero) digits is 34992, while the sum is 41.

The square root of 990689 is about 995.3336124134. Note that the first 3 decimals coincide. The cubic root of 990689 is about 99.6886650447.

The spelling of 990689 in words is "nine hundred ninety thousand, six hundred eighty-nine".