241991 has 4 divisors (see below), whose sum is σ = 244800. Its totient is φ = 239184.

The previous prime is 241981. The next prime is 241993. The reversal of 241991 is 199142.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199142 = 2 ⋅99571.

It is a cyclic number.

It is not a de Polignac number, because 241991 - 2¹⁰ = 240967 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 241991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (241993) 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, 1271 + ... + 1448.

It is an arithmetic number, because the mean of its divisors is an integer number (61200).

2²⁴¹⁹⁹¹ is an apocalyptic number.

241991 is a deficient number, since it is larger than the sum of its proper divisors (2809).

241991 is an equidigital number, since it uses as much as digits as its factorization.

241991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2808.

The product of its digits is 648, while the sum is 26.

The square root of 241991 is about 491.9258074141. The cubic root of 241991 is about 62.3160243118.

Subtracting from 241991 its reverse (199142), we obtain a square (42849 = 207²).

The spelling of 241991 in words is "two hundred forty-one thousand, nine hundred ninety-one".