191001 has 4 divisors (see below), whose sum is σ = 254672. Its totient is φ = 127332.

The previous prime is 190997. The next prime is 191021. The reversal of 191001 is 100191.

191001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 191001 - 2² = 190997 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

191001 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (191021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31831 + ... + 31836.

It is an arithmetic number, because the mean of its divisors is an integer number (63668).

2¹⁹¹⁰⁰¹ is an apocalyptic number.

It is an amenable number.

191001 is a deficient number, since it is larger than the sum of its proper divisors (63671).

191001 is an equidigital number, since it uses as much as digits as its factorization.

191001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63670.

The product of its (nonzero) digits is 9, while the sum is 12.

The square root of 191001 is about 437.0366117387. The cubic root of 191001 is about 57.5897527102.

Adding to 191001 its reverse (100191), we get a palindrome (291192).

The spelling of 191001 in words is "one hundred ninety-one thousand, one".