194991 has 4 divisors (see below), whose sum is σ = 259992. Its totient is φ = 129992.

The previous prime is 194989. The next prime is 195023. The reversal of 194991 is 199491.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 194991 - 2¹ = 194989 is a prime.

It is a D-number.

194991 is a lucky number.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (194911) 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 in 3 ways as a sum of consecutive naturals, for example, 32496 + ... + 32501.

It is an arithmetic number, because the mean of its divisors is an integer number (64998).

2¹⁹⁴⁹⁹¹ is an apocalyptic number.

194991 is a deficient number, since it is larger than the sum of its proper divisors (65001).

194991 is an equidigital number, since it uses as much as digits as its factorization.

194991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65000.

The product of its digits is 2916, while the sum is 33.

The square root of 194991 is about 441.5778527055. The cubic root of 194991 is about 57.9880078258.

The spelling of 194991 in words is "one hundred ninety-four thousand, nine hundred ninety-one".