666166110065 has 4 divisors (see below), whose sum is σ = 799399332084. Its totient is φ = 532932888048.

The previous prime is 666166110061. The next prime is 666166110079. The reversal of 666166110065 is 560011661666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 150181051024 + 515985059041 = 387532^2 + 718321^2 .

It is a cyclic number.

It is not a de Polignac number, because 666166110065 - 2² = 666166110061 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 666166109998 and 666166110025.

It is not an unprimeable number, because it can be changed into a prime (666166110061) 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 3 ways as a sum of consecutive naturals, for example, 66616611002 + ... + 66616611011.

It is an arithmetic number, because the mean of its divisors is an integer number (199849833021).

Almost surely, 2^666166110065 is an apocalyptic number.

It is an amenable number.

666166110065 is a deficient number, since it is larger than the sum of its proper divisors (133233222019).

666166110065 is a wasteful number, since it uses less digits than its factorization.

666166110065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133233222018.

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 666166110065 in words is "six hundred sixty-six billion, one hundred sixty-six million, one hundred ten thousand, sixty-five".