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180181 is a prime number
BaseRepresentation
bin101011111111010101
3100011011101
4223333111
521231211
63510101
71350211
oct537725
9304141
10180181
11113411
1288331
1364021
1449941
15385c1
hex2bfd5

180181 has 2 divisors, whose sum is σ = 180182. Its totient is φ = 180180.

The previous prime is 180179. The next prime is 180211. The reversal of 180181 is 181081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133956 + 46225 = 366^2 + 215^2 .

It is an emirp because it is prime and its reverse (181081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 180181 - 21 = 180179 is a prime.

It is a super-2 number, since 2×1801812 = 64930385522, which contains 22 as substring.

Together with 180179, it forms a pair of twin primes.

It is an Ulam number.

It is a nialpdrome in base 12.

It is a zygodrome in base 4.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (180161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90090 + 90091.

It is an arithmetic number, because the mean of its divisors is an integer number (90091).

2180181 is an apocalyptic number.

It is an amenable number.

180181 is a deficient number, since it is larger than the sum of its proper divisors (1).

180181 is an equidigital number, since it uses as much as digits as its factorization.

180181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 19.

The square root of 180181 is about 424.4773256606. The cubic root of 180181 is about 56.4810806731.

Subtracting 180181 from its reverse (181081), we obtain a square (900 = 302).

It can be divided in two parts, 180 and 181, that added together give a square (361 = 192).

The spelling of 180181 in words is "one hundred eighty thousand, one hundred eighty-one".