1666105156065 has 32 divisors (see below), whose sum is σ = 3144869462016. Its totient is φ = 737078777280.

The previous prime is 1666105156039. The next prime is 1666105156069. The reversal of 1666105156065 is 5606515016661.

It is not a de Polignac number, because 1666105156065 - 2¹⁵ = 1666105123297 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1666105156069) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 255926877 + ... + 255933386.

It is an arithmetic number, because the mean of its divisors is an integer number (98277170688).

Almost surely, 2^{1666105156065} is an apocalyptic number.

1666105156065 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1666105156065 is a deficient number, since it is larger than the sum of its proper divisors (1478764305951).

1666105156065 is a wasteful number, since it uses less digits than its factorization.

1666105156065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511860309.

The product of its (nonzero) digits is 972000, while the sum is 48.

The spelling of 1666105156065 in words is "one trillion, six hundred sixty-six billion, one hundred five million, one hundred fifty-six thousand, sixty-five".