671969 has 2 divisors, whose sum is σ = 671970. Its totient is φ = 671968.

The previous prime is 671947. The next prime is 671971. The reversal of 671969 is 969176.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 664225 + 7744 = 815^2 + 88^2 .

It is a cyclic number.

It is not a de Polignac number, because 671969 - 2¹⁶ = 606433 is a prime.

It is a super-2 number, since 2×671969² = 903084673922, which contains 22 as substring.

Together with 671971, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (671939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335984 + 335985.

It is an arithmetic number, because the mean of its divisors is an integer number (335985).

2⁶⁷¹⁹⁶⁹ is an apocalyptic number.

It is an amenable number.

671969 is a deficient number, since it is larger than the sum of its proper divisors (1).

671969 is an equidigital number, since it uses as much as digits as its factorization.

671969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20412, while the sum is 38.

The square root of 671969 is about 819.7371529948. The cubic root of 671969 is about 87.5890359011.

The spelling of 671969 in words is "six hundred seventy-one thousand, nine hundred sixty-nine".