660550021217 has 8 divisors (see below), whose sum is σ = 705595339656. Its totient is φ = 616192417792.

The previous prime is 660550021213. The next prime is 660550021273. The reversal of 660550021217 is 712120055066.

660550021217 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 165153644881 + 495396376336 = 406391^2 + 703844^2 .

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 660550021217 - 2² = 660550021213 is a prime.

It is a super-2 number, since 2×660550021217² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660550021213) 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, 171926768 + ... + 171930609.

It is an arithmetic number, because the mean of its divisors is an integer number (88199417457).

Almost surely, 2^660550021217 is an apocalyptic number.

It is an amenable number.

660550021217 is a deficient number, since it is larger than the sum of its proper divisors (45045318439).

660550021217 is a wasteful number, since it uses less digits than its factorization.

660550021217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343857507.

The product of its (nonzero) digits is 25200, while the sum is 35.

The spelling of 660550021217 in words is "six hundred sixty billion, five hundred fifty million, twenty-one thousand, two hundred seventeen".