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7081 = 7397
BaseRepresentation
bin1101110101001
3100201021
41232221
5211311
652441
726434
oct15651
910637
107081
115358
124121
1332b9
14281b
152171
hex1ba9

• Sorting the digits of 27081 in ascending order we obtain a prime of 1924 digits.


7081 has 4 divisors (see below), whose sum is σ = 7252. Its totient is φ = 6912.

The previous prime is 7079. The next prime is 7103. The reversal of 7081 is 1807.

7081 = 592 + 602.

7081 is nontrivially palindromic in base 8.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1807 = 13139.

It can be written as a sum of positive squares in 2 ways, for example, as 3600 + 3481 = 60^2 + 59^2 .

It is a 3-Lehmer number, since φ(7081) divides (7081-1)3.

It is a cyclic number.

It is not a de Polignac number, because 7081 - 21 = 7079 is a prime.

It is a super-2 number, since 2×70812 = 100281122, which contains 22 as substring.

It is a Duffinian number.

7081 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (7001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25 + ... + 121.

It is an arithmetic number, because the mean of its divisors is an integer number (1813).

7081 is the 60-th centered square number.

It is an amenable number.

7081 is a deficient number, since it is larger than the sum of its proper divisors (171).

7081 is an equidigital number, since it uses as much as digits as its factorization.

7081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170.

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 7081 is about 84.1486779456. The cubic root of 7081 is about 19.2028135344.

Adding to 7081 its reverse (1807), we get a palindrome (8888).

It can be divided in two parts, 70 and 81, that added together give a palindrome (151).

The spelling of 7081 in words is "seven thousand, eighty-one".

Divisors: 1 73 97 7081