2172145866645 has 16 divisors (see below), whose sum is σ = 3475545318720. Its totient is φ = 1158440484864.

The previous prime is 2172145866601. The next prime is 2172145866677. The reversal of 2172145866645 is 5466685412712.

It is a happy number.

It is not a de Polignac number, because 2172145866645 - 2⁶ = 2172145866581 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1847404 + ... + 2785173.

It is an arithmetic number, because the mean of its divisors is an integer number (217221582420).

Almost surely, 2^{2172145866645} is an apocalyptic number.

It is an amenable number.

2172145866645 is a deficient number, since it is larger than the sum of its proper divisors (1303399452075).

2172145866645 is a wasteful number, since it uses less digits than its factorization.

2172145866645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4663844.

The product of its digits is 19353600, while the sum is 57.

The spelling of 2172145866645 in words is "two trillion, one hundred seventy-two billion, one hundred forty-five million, eight hundred sixty-six thousand, six hundred forty-five".