666165605031 has 12 divisors (see below), whose sum is σ = 962309169640. Its totient is φ = 444078113040.

The previous prime is 666165604957. The next prime is 666165605089. The reversal of 666165605031 is 130506561666.

It is not a de Polignac number, because 666165605031 - 2¹¹ = 666165602983 is a prime.

It is a super-2 number, since 2×666165605031² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666165605531) 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 11 ways as a sum of consecutive naturals, for example, 2559865 + ... + 2808066.

Almost surely, 2^666165605031 is an apocalyptic number.

666165605031 is a deficient number, since it is larger than the sum of its proper divisors (296143564609).

666165605031 is a wasteful number, since it uses less digits than its factorization.

666165605031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5381726 (or 5381723 counting only the distinct ones).

The product of its (nonzero) digits is 583200, while the sum is 45.

The spelling of 666165605031 in words is "six hundred sixty-six billion, one hundred sixty-five million, six hundred five thousand, thirty-one".