665791211 has 8 divisors (see below), whose sum is σ = 675908064. Its totient is φ = 655695040.

The previous prime is 665791187. The next prime is 665791241. The reversal of 665791211 is 112197566.

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

It is a cyclic number.

It is not a de Polignac number, because 665791211 - 2²⁶ = 598682347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665791241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67295 + ... + 76551.

It is an arithmetic number, because the mean of its divisors is an integer number (84488508).

Almost surely, 2^665791211 is an apocalyptic number.

665791211 is a deficient number, since it is larger than the sum of its proper divisors (10116853).

665791211 is a wasteful number, since it uses less digits than its factorization.

665791211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10341.

The product of its digits is 22680, while the sum is 38.

The square root of 665791211 is about 25802.9302793307. The cubic root of 665791211 is about 873.1979067470.

The spelling of 665791211 in words is "six hundred sixty-five million, seven hundred ninety-one thousand, two hundred eleven".