991010 has 16 divisors (see below), whose sum is σ = 1801656. Its totient is φ = 392448.

The previous prime is 991009. The next prime is 991027. The reversal of 991010 is 10199.

It can be written as a sum of positive squares in 4 ways, for example, as 674041 + 316969 = 821^2 + 563^2 .

It is a Curzon number.

It is an unprimeable 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 in 7 ways as a sum of consecutive naturals, for example, 692 + ... + 1568.

2⁹⁹¹⁰¹⁰ is an apocalyptic number.

991010 is a deficient number, since it is larger than the sum of its proper divisors (810646).

991010 is a wasteful number, since it uses less digits than its factorization.

991010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 997.

The product of its (nonzero) digits is 81, while the sum is 20.

The square root of 991010 is about 995.4948518199. The cubic root of 991010 is about 99.6994308201.

It can be divided in two parts, 9 and 91010, that added together give a palindrome (91019).

The spelling of 991010 in words is "nine hundred ninety-one thousand, ten".