9991685 has 8 divisors (see below), whose sum is σ = 13080096. Its totient is φ = 7266640.

The previous prime is 9991673. The next prime is 9991691. The reversal of 9991685 is 5861999.

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

It is not a de Polignac number, because 9991685 - 2⁴ = 9991669 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90779 + ... + 90888.

It is an arithmetic number, because the mean of its divisors is an integer number (1635012).

Almost surely, 2^9991685 is an apocalyptic number.

It is an amenable number.

9991685 is a deficient number, since it is larger than the sum of its proper divisors (3088411).

9991685 is a wasteful number, since it uses less digits than its factorization.

9991685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181683.

The product of its digits is 174960, while the sum is 47.

The square root of 9991685 is about 3160.9626698207. The cubic root of 9991685 is about 215.3837386967.

It can be divided in two parts, 99916 and 85, that added together give a palindrome (100001).

The spelling of 9991685 in words is "nine million, nine hundred ninety-one thousand, six hundred eighty-five".