990664 has 8 divisors (see below), whose sum is σ = 1857510. Its totient is φ = 495328.

The previous prime is 990643. The next prime is 990673. The reversal of 990664 is 466099.

It can be written as a sum of positive squares in only one way, i.e., 917764 + 72900 = 958^2 + 270^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a plaindrome in base 13.

It is an unprimeable number.

990664 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 61909 + ... + 61924.

2⁹⁹⁰⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

990664 is a deficient number, since it is larger than the sum of its proper divisors (866846).

990664 is a wasteful number, since it uses less digits than its factorization.

990664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123839 (or 123835 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 990664 is about 995.3210537309. The cubic root of 990664 is about 99.6878264911.

The spelling of 990664 in words is "nine hundred ninety thousand, six hundred sixty-four".