286991 has 4 divisors (see below), whose sum is σ = 288672. Its totient is φ = 285312.

The previous prime is 286987. The next prime is 286999. The reversal of 286991 is 199682.

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 286991 - 2² = 286987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 286991.

It is not an unprimeable number, because it can be changed into a prime (286999) 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, 551 + ... + 936.

It is an arithmetic number, because the mean of its divisors is an integer number (72168).

2²⁸⁶⁹⁹¹ is an apocalyptic number.

286991 is a deficient number, since it is larger than the sum of its proper divisors (1681).

286991 is a wasteful number, since it uses less digits than its factorization.

286991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1680.

The product of its digits is 7776, while the sum is 35.

The square root of 286991 is about 535.7154095226. The cubic root of 286991 is about 65.9613333353.

The spelling of 286991 in words is "two hundred eighty-six thousand, nine hundred ninety-one".