991715 has 8 divisors (see below), whose sum is σ = 1196448. Its totient is φ = 789120.

The previous prime is 991703. The next prime is 991717. The reversal of 991715 is 517199.

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

It is not a de Polignac number, because 991715 - 2⁶ = 991651 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 991715.

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 (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 794 + ... + 1616.

It is an arithmetic number, because the mean of its divisors is an integer number (149556).

2⁹⁹¹⁷¹⁵ is an apocalyptic number.

991715 is a deficient number, since it is larger than the sum of its proper divisors (204733).

991715 is a wasteful number, since it uses less digits than its factorization.

991715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1069.

The product of its digits is 2835, while the sum is 32.

The square root of 991715 is about 995.8488841185. The cubic root of 991715 is about 99.7230671231.

The spelling of 991715 in words is "nine hundred ninety-one thousand, seven hundred fifteen".