666021701617 has 8 divisors (see below), whose sum is σ = 688997269440. Its totient is φ = 643046754000.

The previous prime is 666021701507. The next prime is 666021701659. The reversal of 666021701617 is 716107120666.

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

It is not a de Polignac number, because 666021701617 - 2¹¹ = 666021699569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666021701677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3453492 + ... + 3641242.

It is an arithmetic number, because the mean of its divisors is an integer number (86124658680).

Almost surely, 2^666021701617 is an apocalyptic number.

It is an amenable number.

666021701617 is a deficient number, since it is larger than the sum of its proper divisors (22975567823).

666021701617 is a wasteful number, since it uses less digits than its factorization.

666021701617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310103.

The product of its (nonzero) digits is 127008, while the sum is 43.

The spelling of 666021701617 in words is "six hundred sixty-six billion, twenty-one million, seven hundred one thousand, six hundred seventeen".