644671170589 has 4 divisors (see below), whose sum is σ = 644860060956. Its totient is φ = 644482280224.

The previous prime is 644671170569. The next prime is 644671170601. The reversal of 644671170589 is 985071176446.

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 552219903225 + 92451267364 = 743115^2 + 304058^2 .

It is a cyclic number.

It is not a de Polignac number, because 644671170589 - 2⁵ = 644671170557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644671170569) 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, 94440064 + ... + 94446889.

It is an arithmetic number, because the mean of its divisors is an integer number (161215015239).

Almost surely, 2^644671170589 is an apocalyptic number.

It is an amenable number.

644671170589 is a deficient number, since it is larger than the sum of its proper divisors (188890367).

644671170589 is a wasteful number, since it uses less digits than its factorization.

644671170589 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188890366.

The product of its (nonzero) digits is 10160640, while the sum is 58.

The spelling of 644671170589 in words is "six hundred forty-four billion, six hundred seventy-one million, one hundred seventy thousand, five hundred eighty-nine".