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20287 is a prime number
BaseRepresentation
bin100111100111111
31000211101
410330333
51122122
6233531
7113101
oct47477
930741
1020287
1114273
12b8a7
139307
147571
156027
hex4f3f

20287 has 2 divisors, whose sum is σ = 20288. Its totient is φ = 20286.

The previous prime is 20269. The next prime is 20297. The reversal of 20287 is 78202.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-20287 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10143 + 10144.

It is an arithmetic number, because the mean of its divisors is an integer number (10144).

220287 is an apocalyptic number.

20287 is a deficient number, since it is larger than the sum of its proper divisors (1).

20287 is an equidigital number, since it uses as much as digits as its factorization.

20287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 20287 is about 142.4324401251. The cubic root of 20287 is about 27.2733996467.

Adding to 20287 its reverse (78202), we get a palindrome (98489).

It can be divided in two parts, 2028 and 7, that multiplied together give a triangular number (14196 = T168).

The spelling of 20287 in words is "twenty thousand, two hundred eighty-seven".