666107721723 has 8 divisors (see below), whose sum is σ = 888271062336. Its totient is φ = 444008097800.

The previous prime is 666107721701. The next prime is 666107721743. The reversal of 666107721723 is 327127701666.

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 666107721723 - 2⁹ = 666107721211 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666107721743) 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, 15904773 + ... + 15946598.

It is an arithmetic number, because the mean of its divisors is an integer number (111033882792).

Almost surely, 2^666107721723 is an apocalyptic number.

666107721723 is a deficient number, since it is larger than the sum of its proper divisors (222163340613).

666107721723 is a wasteful number, since it uses less digits than its factorization.

666107721723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31858345.

The product of its (nonzero) digits is 889056, while the sum is 48.

The spelling of 666107721723 in words is "six hundred sixty-six billion, one hundred seven million, seven hundred twenty-one thousand, seven hundred twenty-three".