673445664 has 120 divisors (see below), whose sum is σ = 2029212108. Its totient is φ = 218972160.

The previous prime is 673445603. The next prime is 673445677. The reversal of 673445664 is 466544376.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 590490000 + 82955664 = 24300^2 + 9108^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 103104 + ... + 109440.

Almost surely, 2^673445664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 673445664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1014606054).

673445664 is an abundant number, since it is smaller than the sum of its proper divisors (1355766444).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

673445664 is a wasteful number, since it uses less digits than its factorization.

673445664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6400 (or 6383 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 45.

The square root of 673445664 is about 25950.8316629737. The cubic root of 673445664 is about 876.5314845670.

The spelling of 673445664 in words is "six hundred seventy-three million, four hundred forty-five thousand, six hundred sixty-four".