287911 has 4 divisors (see below), whose sum is σ = 310072. Its totient is φ = 265752.

The previous prime is 287887. The next prime is 287921. The reversal of 287911 is 119782.

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 287911 - 2⁷ = 287783 is a prime.

It is a Duffinian number.

287911 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 287911.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (287921) 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, 11061 + ... + 11086.

It is an arithmetic number, because the mean of its divisors is an integer number (77518).

2²⁸⁷⁹¹¹ is an apocalyptic number.

287911 is a deficient number, since it is larger than the sum of its proper divisors (22161).

287911 is a wasteful number, since it uses less digits than its factorization.

287911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22160.

The product of its digits is 1008, while the sum is 28.

The square root of 287911 is about 536.5733873386. The cubic root of 287911 is about 66.0317416954.

Subtracting from 287911 its product of digits (1008), we obtain a triangular number (286903 = T₇₅₇).

The spelling of 287911 in words is "two hundred eighty-seven thousand, nine hundred eleven".