10001666010665 has 16 divisors (see below), whose sum is σ = 14523427619712. Its totient is φ = 6454856719104.

The previous prime is 10001666010659. The next prime is 10001666010673. The reversal of 10001666010665 is 56601066610001.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 10001666010665 - 2¹⁰ = 10001666009641 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8404760759 + ... + 8404761948.

It is an arithmetic number, because the mean of its divisors is an integer number (907714226232).

Almost surely, 2^{10001666010665} is an apocalyptic number.

It is an amenable number.

10001666010665 is a deficient number, since it is larger than the sum of its proper divisors (4521761609047).

10001666010665 is a wasteful number, since it uses less digits than its factorization.

10001666010665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16809522736.

The product of its (nonzero) digits is 38880, while the sum is 38.

It can be divided in two parts, 10001 and 666010665, that added together give a palindrome (666020666).

The spelling of 10001666010665 in words is "ten trillion, one billion, six hundred sixty-six million, ten thousand, six hundred sixty-five".