665656611 has 8 divisors (see below), whose sum is σ = 888053760. Its totient is φ = 443515272.

The previous prime is 665656609. The next prime is 665656613. The reversal of 665656611 is 116656566.

It is an interprime number because it is at equal distance from previous prime (665656609) and next prime (665656613).

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

It is not a de Polignac number, because 665656611 - 2¹ = 665656609 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (665656613) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57795 + ... + 68348.

It is an arithmetic number, because the mean of its divisors is an integer number (111006720).

Almost surely, 2^665656611 is an apocalyptic number.

665656611 is a deficient number, since it is larger than the sum of its proper divisors (222397149).

665656611 is a wasteful number, since it uses less digits than its factorization.

665656611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127905.

The product of its digits is 194400, while the sum is 42.

The square root of 665656611 is about 25800.3219165963. The cubic root of 665656611 is about 873.1390592898.

The spelling of 665656611 in words is "six hundred sixty-five million, six hundred fifty-six thousand, six hundred eleven".