102181 has 2 divisors, whose sum is σ = 102182. Its totient is φ = 102180.

The previous prime is 102161. The next prime is 102191. The reversal of 102181 is 181201.

It is the 131-st star number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58081 + 44100 = 241^2 + 210^2 .

It is an emirp because it is prime and its reverse (181201) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 102181 - 2⁵ = 102149 is a prime.

It is a super-4 number, since 4×102181⁴ (a number of 21 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51090 + 51091.

It is an arithmetic number, because the mean of its divisors is an integer number (51091).

2¹⁰²¹⁸¹ is an apocalyptic number.

It is an amenable number.

102181 is a deficient number, since it is larger than the sum of its proper divisors (1).

102181 is an equidigital number, since it uses as much as digits as its factorization.

102181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 102181 is about 319.6576293474. The cubic root of 102181 is about 46.7509079294.

Adding to 102181 its reverse (181201), we get a palindrome (283382).

The spelling of 102181 in words is "one hundred two thousand, one hundred eighty-one".