991711 has 12 divisors (see below), whose sum is σ = 1186968. Its totient is φ = 825552.

The previous prime is 991703. The next prime is 991717. The reversal of 991711 is 117199.

It is not a de Polignac number, because 991711 - 2³ = 991703 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 991711.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991717) 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 11 ways as a sum of consecutive naturals, for example, 1540 + ... + 2086.

It is an arithmetic number, because the mean of its divisors is an integer number (98914).

2⁹⁹¹⁷¹¹ is an apocalyptic number.

991711 is a deficient number, since it is larger than the sum of its proper divisors (195257).

991711 is a wasteful number, since it uses less digits than its factorization.

991711 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 598 (or 591 counting only the distinct ones).

The product of its digits is 567, while the sum is 28.

The square root of 991711 is about 995.8468757796. The cubic root of 991711 is about 99.7229330480.

The spelling of 991711 in words is "nine hundred ninety-one thousand, seven hundred eleven".