671749 has 4 divisors (see below), whose sum is σ = 723436. Its totient is φ = 620064.

The previous prime is 671743. The next prime is 671753. The reversal of 671749 is 947176.

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 431649 + 240100 = 657^2 + 490^2 .

It is a cyclic number.

It is not a de Polignac number, because 671749 - 2⁵ = 671717 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 (671743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25824 + ... + 25849.

It is an arithmetic number, because the mean of its divisors is an integer number (180859).

2⁶⁷¹⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

671749 is a deficient number, since it is larger than the sum of its proper divisors (51687).

671749 is a wasteful number, since it uses less digits than its factorization.

671749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51686.

The product of its digits is 10584, while the sum is 34.

The square root of 671749 is about 819.6029526545. The cubic root of 671749 is about 87.5794760895.

The spelling of 671749 in words is "six hundred seventy-one thousand, seven hundred forty-nine".