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138581 is a prime number
BaseRepresentation
bin100001110101010101
321001002122
4201311111
513413311
62545325
71115012
oct416525
9231078
10138581
1195133
1268245
134b101
1438709
152b0db
hex21d55

138581 has 2 divisors, whose sum is σ = 138582. Its totient is φ = 138580.

The previous prime is 138577. The next prime is 138587. The reversal of 138581 is 185831.

138581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 136900 + 1681 = 370^2 + 41^2 .

It is an emirp because it is prime and its reverse (185831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138581 - 22 = 138577 is a prime.

It is a super-2 number, since 2×1385812 = 38409387122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is an Ulam number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 138581.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 138581.

It is not a weakly prime, because it can be changed into another prime (138587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69290 + 69291.

It is an arithmetic number, because the mean of its divisors is an integer number (69291).

2138581 is an apocalyptic number.

It is an amenable number.

138581 is a deficient number, since it is larger than the sum of its proper divisors (1).

138581 is an equidigital number, since it uses as much as digits as its factorization.

138581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 960, while the sum is 26.

The square root of 138581 is about 372.2646907779. The cubic root of 138581 is about 51.7489128262.

The spelling of 138581 in words is "one hundred thirty-eight thousand, five hundred eighty-one".