991085 has 8 divisors (see below), whose sum is σ = 1194720. Its totient is φ = 789264.

The previous prime is 991079. The next prime is 991091. The reversal of 991085 is 580199.

It is an interprime number because it is at equal distance from previous prime (991079) and next prime (991091).

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

It is a cyclic number.

It is not a de Polignac number, because 991085 - 2⁴ = 991069 is a prime.

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, 1634 + ... + 2156.

It is an arithmetic number, because the mean of its divisors is an integer number (149340).

2⁹⁹¹⁰⁸⁵ is an apocalyptic number.

It is an amenable number.

991085 is a deficient number, since it is larger than the sum of its proper divisors (203635).

991085 is a wasteful number, since it uses less digits than its factorization.

991085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 907.

The product of its (nonzero) digits is 3240, while the sum is 32.

The square root of 991085 is about 995.5325208149. The cubic root of 991085 is about 99.7019458532.

The spelling of 991085 in words is "nine hundred ninety-one thousand, eighty-five".