671744 has 30 divisors (see below), whose sum is σ = 1376214. Its totient is φ = 327680.

The previous prime is 671743. The next prime is 671753. The reversal of 671744 is 447176.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 409600 + 262144 = 640^2 + 512^2 .

It is a nialpdrome in base 4 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (3) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16364 + ... + 16404.

671744 is a Friedman number, since it can be written as 4^7*(6+7*(4+1)), using all its digits and the basic arithmetic operations.

2⁶⁷¹⁷⁴⁴ is an apocalyptic number.

671744 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 671744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (688107).

671744 is an abundant number, since it is smaller than the sum of its proper divisors (704470).

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

671744 is an frugal number, since it uses more digits than its factorization.

671744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69 (or 43 counting only the distinct ones).

The product of its digits is 4704, while the sum is 29.

The square root of 671744 is about 819.5999023914. The cubic root of 671744 is about 87.5792587968.

The spelling of 671744 in words is "six hundred seventy-one thousand, seven hundred forty-four".