287921 has 2 divisors, whose sum is σ = 287922. Its totient is φ = 287920.

The previous prime is 287887. The next prime is 287933. The reversal of 287921 is 129782.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 287296 + 625 = 536^2 + 25^2 .

It is a cyclic number.

It is not a de Polignac number, because 287921 - 2⁶ = 287857 is a prime.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 287921.

It is not a weakly prime, because it can be changed into another prime (287321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 143960 + 143961.

It is an arithmetic number, because the mean of its divisors is an integer number (143961).

2²⁸⁷⁹²¹ is an apocalyptic number.

It is an amenable number.

287921 is a deficient number, since it is larger than the sum of its proper divisors (1).

287921 is an equidigital number, since it uses as much as digits as its factorization.

287921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 29.

The square root of 287921 is about 536.5827056475. The cubic root of 287921 is about 66.0325061791.

The spelling of 287921 in words is "two hundred eighty-seven thousand, nine hundred twenty-one".