64191 has 4 divisors (see below), whose sum is σ = 85592. Its totient is φ = 42792.

The previous prime is 64189. The next prime is 64217. The reversal of 64191 is 19146.

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

It is not a de Polignac number, because 64191 - 2¹ = 64189 is a prime.

It is a D-number.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64151) 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, 10696 + ... + 10701.

It is an arithmetic number, because the mean of its divisors is an integer number (21398).

2⁶⁴¹⁹¹ is an apocalyptic number.

64191 is a deficient number, since it is larger than the sum of its proper divisors (21401).

64191 is a wasteful number, since it uses less digits than its factorization.

64191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21400.

The product of its digits is 216, while the sum is 21.

The square root of 64191 is about 253.3594284806. The cubic root of 64191 is about 40.0397521477.

The spelling of 64191 in words is "sixty-four thousand, one hundred ninety-one".