2166285851809 has 6 divisors (see below), whose sum is σ = 2264567252066. Its totient is φ = 2072099509920.

The previous prime is 2166285851791. The next prime is 2166285851831. The reversal of 2166285851809 is 9081585826612.

It can be written as a sum of positive squares in only one way, i.e., 1359199227409 + 807086624400 = 1165847^2 + 898380^2 .

It is not a de Polignac number, because 2166285851809 - 2¹⁷ = 2166285720737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2166285821809) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2047528632 + ... + 2047529689.

Almost surely, 2^{2166285851809} is an apocalyptic number.

It is an amenable number.

2166285851809 is a deficient number, since it is larger than the sum of its proper divisors (98281400257).

2166285851809 is an equidigital number, since it uses as much as digits as its factorization.

2166285851809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4095058367 (or 4095058344 counting only the distinct ones).

The product of its (nonzero) digits is 16588800, while the sum is 61.

The spelling of 2166285851809 in words is "two trillion, one hundred sixty-six billion, two hundred eighty-five million, eight hundred fifty-one thousand, eight hundred nine".