287761 has 4 divisors (see below), whose sum is σ = 291312. Its totient is φ = 284212.

The previous prime is 287747. The next prime is 287783. The reversal of 287761 is 167782.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 167782 = 2 ⋅83891.

It is a cyclic number.

It is not a de Polignac number, because 287761 - 2¹⁵ = 254993 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (287701) 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, 1651 + ... + 1816.

It is an arithmetic number, because the mean of its divisors is an integer number (72828).

2²⁸⁷⁷⁶¹ is an apocalyptic number.

It is an amenable number.

287761 is a deficient number, since it is larger than the sum of its proper divisors (3551).

287761 is an equidigital number, since it uses as much as digits as its factorization.

287761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3550.

The product of its digits is 4704, while the sum is 31.

The square root of 287761 is about 536.4335932807. The cubic root of 287761 is about 66.0202723156.

The spelling of 287761 in words is "two hundred eighty-seven thousand, seven hundred sixty-one".