671742436945 has 4 divisors (see below), whose sum is σ = 806090924340. Its totient is φ = 537393949552.

The previous prime is 671742436927. The next prime is 671742436993. The reversal of 671742436945 is 549634247176.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 262700326849 + 409042110096 = 512543^2 + 639564^2 .

It is a cyclic number.

It is not a de Polignac number, because 671742436945 - 2²⁹ = 671205566033 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 671742436945.

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 3 ways as a sum of consecutive naturals, for example, 67174243690 + ... + 67174243699.

It is an arithmetic number, because the mean of its divisors is an integer number (201522731085).

Almost surely, 2^671742436945 is an apocalyptic number.

It is an amenable number.

671742436945 is a deficient number, since it is larger than the sum of its proper divisors (134348487395).

671742436945 is a wasteful number, since it uses less digits than its factorization.

671742436945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134348487394.

The product of its digits is 30481920, while the sum is 58.

The spelling of 671742436945 in words is "six hundred seventy-one billion, seven hundred forty-two million, four hundred thirty-six thousand, nine hundred forty-five".