660071612321 has 16 divisors (see below), whose sum is σ = 721730072448. Its totient is φ = 598689216000.

The previous prime is 660071612293. The next prime is 660071612323. The reversal of 660071612321 is 123216170066.

It is a cyclic number.

It is not a de Polignac number, because 660071612321 - 2⁶ = 660071612257 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (660071612323) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20107121 + ... + 20139921.

It is an arithmetic number, because the mean of its divisors is an integer number (45108129528).

Almost surely, 2^660071612321 is an apocalyptic number.

It is an amenable number.

660071612321 is a deficient number, since it is larger than the sum of its proper divisors (61658460127).

660071612321 is a wasteful number, since it uses less digits than its factorization.

660071612321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36952.

The product of its (nonzero) digits is 18144, while the sum is 35.

Adding to 660071612321 its reverse (123216170066), we get a palindrome (783287782387).

The spelling of 660071612321 in words is "six hundred sixty billion, seventy-one million, six hundred twelve thousand, three hundred twenty-one".