671939 has 2 divisors, whose sum is σ = 671940. Its totient is φ = 671938.

The previous prime is 671933. The next prime is 671941. The reversal of 671939 is 939176.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-671939 is a prime.

Together with 671941, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 6.

It is a junction number, because it is equal to n+sod(n) for n = 671899 and 671908.

It is not a weakly prime, because it can be changed into another prime (671933) 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, 335969 + 335970.

It is an arithmetic number, because the mean of its divisors is an integer number (335970).

2⁶⁷¹⁹³⁹ is an apocalyptic number.

671939 is a deficient number, since it is larger than the sum of its proper divisors (1).

671939 is an equidigital number, since it uses as much as digits as its factorization.

671939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10206, while the sum is 35.

The square root of 671939 is about 819.7188542421. The cubic root of 671939 is about 87.5877324133.

The spelling of 671939 in words is "six hundred seventy-one thousand, nine hundred thirty-nine".