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82721 is a prime number
BaseRepresentation
bin10100001100100001
311012110202
4110030201
510121341
61434545
7463112
oct241441
9135422
1082721
1157171
123ba55
132b862
1422209
151979b
hex14321

82721 has 2 divisors, whose sum is σ = 82722. Its totient is φ = 82720.

The previous prime is 82699. The next prime is 82723. The reversal of 82721 is 12728.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57121 + 25600 = 239^2 + 160^2 .

It is a cyclic number.

It is not a de Polignac number, because 82721 - 26 = 82657 is a prime.

It is a Sophie Germain prime.

Together with 82723, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 82693 and 82702.

It is not a weakly prime, because it can be changed into another prime (82723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41360 + 41361.

It is an arithmetic number, because the mean of its divisors is an integer number (41361).

282721 is an apocalyptic number.

It is an amenable number.

82721 is a deficient number, since it is larger than the sum of its proper divisors (1).

82721 is an equidigital number, since it uses as much as digits as its factorization.

82721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 224, while the sum is 20.

The square root of 82721 is about 287.6125866509. The cubic root of 82721 is about 43.5717756336.

It can be divided in two parts, 827 and 21, that added together give a palindrome (848).

The spelling of 82721 in words is "eighty-two thousand, seven hundred twenty-one".