991006 has 8 divisors (see below), whose sum is σ = 1511064. Its totient is φ = 487320.

The previous prime is 990989. The next prime is 991009. The reversal of 991006 is 600199.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3940 + ... + 4183.

It is an arithmetic number, because the mean of its divisors is an integer number (188883).

2⁹⁹¹⁰⁰⁶ is an apocalyptic number.

991006 is a deficient number, since it is larger than the sum of its proper divisors (520058).

991006 is a wasteful number, since it uses less digits than its factorization.

991006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8186.

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 991006 is about 995.4928427668. The cubic root of 991006 is about 99.6992966815.

The spelling of 991006 in words is "nine hundred ninety-one thousand, six".