786991 has 4 divisors (see below), whose sum is σ = 821232. Its totient is φ = 752752.

The previous prime is 786983. The next prime is 787021. The reversal of 786991 is 199687.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 786991 - 2³ = 786983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (786901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17086 + ... + 17131.

It is an arithmetic number, because the mean of its divisors is an integer number (205308).

2⁷⁸⁶⁹⁹¹ is an apocalyptic number.

786991 is a deficient number, since it is larger than the sum of its proper divisors (34241).

786991 is a wasteful number, since it uses less digits than its factorization.

786991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34240.

The product of its digits is 27216, while the sum is 40.

The square root of 786991 is about 887.1251320981. The cubic root of 786991 is about 92.3258373696.

The spelling of 786991 in words is "seven hundred eighty-six thousand, nine hundred ninety-one".