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287281 is a prime number
BaseRepresentation
bin1000110001000110001
3112121002001
41012020301
533143111
610054001
72304361
oct1061061
9477061
10287281
11186925
1211a301
13a09b7
14769a1
155a1c1
hex46231

287281 has 2 divisors, whose sum is σ = 287282. Its totient is φ = 287280.

The previous prime is 287279. The next prime is 287291. The reversal of 287281 is 182782.

287281 is nontrivially palindromic in base 2.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 266256 + 21025 = 516^2 + 145^2 .

It is a cyclic number.

It is not a de Polignac number, because 287281 - 21 = 287279 is a prime.

It is a super-2 number, since 2×2872812 = 165060745922, which contains 22 as substring.

Together with 287279, it forms a pair of twin primes.

287281 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (287251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 143640 + 143641.

It is an arithmetic number, because the mean of its divisors is an integer number (143641).

2287281 is an apocalyptic number.

It is an amenable number.

287281 is a deficient number, since it is larger than the sum of its proper divisors (1).

287281 is an equidigital number, since it uses as much as digits as its factorization.

287281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1792, while the sum is 28.

The square root of 287281 is about 535.9860072800. The cubic root of 287281 is about 65.9835434942.

The spelling of 287281 in words is "two hundred eighty-seven thousand, two hundred eighty-one".