287993 has 4 divisors (see below), whose sum is σ = 291060. Its totient is φ = 284928.

The previous prime is 287977. The next prime is 288007. The reversal of 287993 is 399782.

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

It can be written as a sum of positive squares in 2 ways, for example, as 44944 + 243049 = 212^2 + 493^2 .

It is a cyclic number.

It is not a de Polignac number, because 287993 - 2⁴ = 287977 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (287933) 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, 1388 + ... + 1581.

It is an arithmetic number, because the mean of its divisors is an integer number (72765).

2²⁸⁷⁹⁹³ is an apocalyptic number.

It is an amenable number.

287993 is a deficient number, since it is larger than the sum of its proper divisors (3067).

287993 is an equidigital number, since it uses as much as digits as its factorization.

287993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3066.

The product of its digits is 27216, while the sum is 38.

The square root of 287993 is about 536.6497926954. The cubic root of 287993 is about 66.0380099390.

The spelling of 287993 in words is "two hundred eighty-seven thousand, nine hundred ninety-three".