671729 has 2 divisors, whose sum is σ = 671730. Its totient is φ = 671728.

The previous prime is 671717. The next prime is 671743. The reversal of 671729 is 927176.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 559504 + 112225 = 748^2 + 335^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-671729 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 671695 and 671704.

It is not a weakly prime, because it can be changed into another prime (671779) by changing a digit.

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 as a sum of consecutive naturals, namely, 335864 + 335865.

It is an arithmetic number, because the mean of its divisors is an integer number (335865).

2⁶⁷¹⁷²⁹ is an apocalyptic number.

It is an amenable number.

671729 is a deficient number, since it is larger than the sum of its proper divisors (1).

671729 is an equidigital number, since it uses as much as digits as its factorization.

671729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5292, while the sum is 32.

The square root of 671729 is about 819.5907515340. The cubic root of 671729 is about 87.5786069122.

The spelling of 671729 in words is "six hundred seventy-one thousand, seven hundred twenty-nine".