191801 has 2 divisors, whose sum is σ = 191802. Its totient is φ = 191800.

The previous prime is 191791. The next prime is 191803. The reversal of 191801 is 108191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 102400 + 89401 = 320^2 + 299^2 .

It is an emirp because it is prime and its reverse (108191) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191801 is a prime.

Together with 191803, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (191803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95900 + 95901.

It is an arithmetic number, because the mean of its divisors is an integer number (95901).

2¹⁹¹⁸⁰¹ is an apocalyptic number.

It is an amenable number.

191801 is a deficient number, since it is larger than the sum of its proper divisors (1).

191801 is an equidigital number, since it uses as much as digits as its factorization.

191801 is an odious number, because the sum of its binary digits is odd.

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

The square root of 191801 is about 437.9509104911. The cubic root of 191801 is about 57.6700448346.

Adding to 191801 its reverse (108191), we get a palindrome (299992).

The spelling of 191801 in words is "one hundred ninety-one thousand, eight hundred one".