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65281 = 97673
BaseRepresentation
bin1111111100000001
310022112211
433330001
54042111
61222121
7361216
oct177401
9108484
1065281
1145057
1231941
1323938
1419b0d
1514521
hexff01

65281 has 4 divisors (see below), whose sum is σ = 66052. Its totient is φ = 64512.

The previous prime is 65269. The next prime is 65287. The reversal of 65281 is 18256.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25281 + 40000 = 159^2 + 200^2 .

It is a cyclic number.

It is not a de Polignac number, because 65281 - 213 = 57089 is a prime.

It is a super-2 number, since 2×652812 = 8523217922, which contains 22 as substring.

It is the 256-th Hogben number.

It is a Duffinian number.

65281 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (65287) by changing a digit.

It is a nontrivial repunit in base 255.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 240 + ... + 433.

It is an arithmetic number, because the mean of its divisors is an integer number (16513).

It is a Proth number, since it is equal to 255 ⋅ 28 + 1 and 255 < 28.

It is a Poulet number, since it divides 265280-1.

265281 is an apocalyptic number.

It is an amenable number.

65281 is a deficient number, since it is larger than the sum of its proper divisors (771).

65281 is an equidigital number, since it uses as much as digits as its factorization.

65281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 770.

The product of its digits is 480, while the sum is 22.

The square root of 65281 is about 255.5014677062. The cubic root of 65281 is about 40.2651139824.

The spelling of 65281 in words is "sixty-five thousand, two hundred eighty-one".

Divisors: 1 97 673 65281