671777 has 2 divisors, whose sum is σ = 671778. Its totient is φ = 671776.

The previous prime is 671753. The next prime is 671779. The reversal of 671777 is 777176.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 614656 + 57121 = 784^2 + 239^2 .

It is a cyclic number.

It is not a de Polignac number, because 671777 - 2¹⁶ = 606241 is a prime.

Together with 671779, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 9.

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 (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335888 + 335889.

It is an arithmetic number, because the mean of its divisors is an integer number (335889).

2⁶⁷¹⁷⁷⁷ is an apocalyptic number.

It is an amenable number.

671777 is a deficient number, since it is larger than the sum of its proper divisors (1).

671777 is an equidigital number, since it uses as much as digits as its factorization.

671777 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14406, while the sum is 35.

The square root of 671777 is about 819.6200339182. The cubic root of 671777 is about 87.5806929087.

The spelling of 671777 in words is "six hundred seventy-one thousand, seven hundred seventy-seven".