1645125665173 has 4 divisors (see below), whose sum is σ = 1645131644800. Its totient is φ = 1645119685548.

The previous prime is 1645125665171. The next prime is 1645125665189. The reversal of 1645125665173 is 3715665215461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1645125665173 - 2¹ = 1645125665171 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1645125665173.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645125665171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2556165 + ... + 3134362.

It is an arithmetic number, because the mean of its divisors is an integer number (411282911200).

Almost surely, 2^{1645125665173} is an apocalyptic number.

It is an amenable number.

1645125665173 is a deficient number, since it is larger than the sum of its proper divisors (5979627).

1645125665173 is an equidigital number, since it uses as much as digits as its factorization.

1645125665173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5979626.

The product of its digits is 4536000, while the sum is 52.

The spelling of 1645125665173 in words is "one trillion, six hundred forty-five billion, one hundred twenty-five million, six hundred sixty-five thousand, one hundred seventy-three".