660191 has 8 divisors (see below), whose sum is σ = 775200. Its totient is φ = 550368.

The previous prime is 660181. The next prime is 660197. The reversal of 660191 is 191066.

660191 is nontrivially palindromic in base 5.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-660191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1016 + ... + 1533.

It is an arithmetic number, because the mean of its divisors is an integer number (96900).

2⁶⁶⁰¹⁹¹ is an apocalyptic number.

660191 is a deficient number, since it is larger than the sum of its proper divisors (115009).

660191 is a wasteful number, since it uses less digits than its factorization.

660191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2593.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 660191 is about 812.5213843340. The cubic root of 660191 is about 87.0742748807.

The spelling of 660191 in words is "six hundred sixty thousand, one hundred ninety-one".