91643 has 4 divisors (see below), whose sum is σ = 92568. Its totient is φ = 90720.

The previous prime is 91639. The next prime is 91673. The reversal of 91643 is 34619.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 34619 = 13 ⋅2663.

It is a cyclic number.

It is not a de Polignac number, because 91643 - 2² = 91639 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (91673) 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, 293 + ... + 518.

It is an arithmetic number, because the mean of its divisors is an integer number (23142).

2⁹¹⁶⁴³ is an apocalyptic number.

91643 is a deficient number, since it is larger than the sum of its proper divisors (925).

91643 is a wasteful number, since it uses less digits than its factorization.

91643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 924.

The product of its digits is 648, while the sum is 23.

The square root of 91643 is about 302.7259486731. The cubic root of 91643 is about 45.0851064304.

It can be divided in two parts, 916 and 43, that added together give a palindrome (959).

The spelling of 91643 in words is "ninety-one thousand, six hundred forty-three".