19181 has 2 divisors, whose sum is σ = 19182. Its totient is φ = 19180.

The previous prime is 19163. The next prime is 19183. The reversal of 19181 is 18191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17956 + 1225 = 134^2 + 35^2 .

It is an emirp because it is prime and its reverse (18191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19181 - 2¹⁴ = 2797 is a prime.

It is a super-2 number, since 2×19181² = 735821522, which contains 22 as substring.

Together with 19183, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 6 and base 11.

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 19181.

It is not a weakly prime, because it can be changed into another prime (19183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9590 + 9591.

It is an arithmetic number, because the mean of its divisors is an integer number (9591).

2¹⁹¹⁸¹ is an apocalyptic number.

It is an amenable number.

19181 is a deficient number, since it is larger than the sum of its proper divisors (1).

19181 is an equidigital number, since it uses as much as digits as its factorization.

19181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72, while the sum is 20.

The square root of 19181 is about 138.4954872911. The cubic root of 19181 is about 26.7684822922.

Subtracting from 19181 its reverse (18191), we obtain a triangular number (990 = T₄₄).

It can be divided in two parts, 191 and 81, that added together give a palindrome (272).

The spelling of 19181 in words is "nineteen thousand, one hundred eighty-one".