41991 has 4 divisors (see below), whose sum is σ = 55992. Its totient is φ = 27992.

The previous prime is 41983. The next prime is 41999. The reversal of 41991 is 19914.

41991 is nontrivially palindromic in base 9 and base 13.

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

It is an interprime number because it is at equal distance from previous prime (41983) and next prime (41999).

It is a cyclic number.

It is not a de Polignac number, because 41991 - 2³ = 41983 is a prime.

It is a D-number.

41991 is an undulating number in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (41999) 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, 6996 + ... + 7001.

It is an arithmetic number, because the mean of its divisors is an integer number (13998).

2⁴¹⁹⁹¹ is an apocalyptic number.

41991 is a deficient number, since it is larger than the sum of its proper divisors (14001).

41991 is a wasteful number, since it uses less digits than its factorization.

41991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14000.

The product of its digits is 324, while the sum is 24.

The square root of 41991 is about 204.9170563911. The cubic root of 41991 is about 34.7577833953.

The spelling of 41991 in words is "forty-one thousand, nine hundred ninety-one".