666038721271 has 16 divisors (see below), whose sum is σ = 857172584448. Its totient is φ = 502249557600.

The previous prime is 666038721263. The next prime is 666038721307. The reversal of 666038721271 is 172127830666.

It is not a de Polignac number, because 666038721271 - 2³ = 666038721263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666038721571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139511380 + ... + 139516153.

It is an arithmetic number, because the mean of its divisors is an integer number (53573286528).

Almost surely, 2^666038721271 is an apocalyptic number.

666038721271 is a deficient number, since it is larger than the sum of its proper divisors (191133863177).

666038721271 is a wasteful number, since it uses less digits than its factorization.

666038721271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279027582.

The product of its (nonzero) digits is 1016064, while the sum is 49.

The spelling of 666038721271 in words is "six hundred sixty-six billion, thirty-eight million, seven hundred twenty-one thousand, two hundred seventy-one".