1666106006665 has 8 divisors (see below), whose sum is σ = 2001927117960. Its totient is φ = 1331151532032.

The previous prime is 1666106006567. The next prime is 1666106006671. The reversal of 1666106006665 is 5666006016661.

It can be written as a sum of positive squares in 4 ways, for example, as 486214738681 + 1179891267984 = 697291^2 + 1086228^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666106006665 is a prime.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 216654934 + ... + 216662623.

It is an arithmetic number, because the mean of its divisors is an integer number (250240889745).

Almost surely, 2^{1666106006665} is an apocalyptic number.

It is an amenable number.

1666106006665 is a deficient number, since it is larger than the sum of its proper divisors (335821111295).

1666106006665 is an equidigital number, since it uses as much as digits as its factorization.

1666106006665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433318331.

The product of its (nonzero) digits is 1399680, while the sum is 49.

The spelling of 1666106006665 in words is "one trillion, six hundred sixty-six billion, one hundred six million, six thousand, six hundred sixty-five".