6660656617 has 4 divisors (see below), whose sum is σ = 6711501456. Its totient is φ = 6609811780.

The previous prime is 6660656609. The next prime is 6660656711. The reversal of 6660656617 is 7166560666.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7166560666 = 2 ⋅3583280333.

It is a cyclic number.

It is not a de Polignac number, because 6660656617 - 2³ = 6660656609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6660650617) 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, 25422223 + ... + 25422484.

It is an arithmetic number, because the mean of its divisors is an integer number (1677875364).

Almost surely, 2^6660656617 is an apocalyptic number.

It is an amenable number.

6660656617 is a deficient number, since it is larger than the sum of its proper divisors (50844839).

6660656617 is a wasteful number, since it uses less digits than its factorization.

6660656617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50844838.

The product of its (nonzero) digits is 1632960, while the sum is 49.

The square root of 6660656617 is about 81612.8459067566. The cubic root of 6660656617 is about 1881.5063203953.

The spelling of 6660656617 in words is "six billion, six hundred sixty million, six hundred fifty-six thousand, six hundred seventeen".