673991 has 2 divisors, whose sum is σ = 673992. Its totient is φ = 673990.

The previous prime is 673979. The next prime is 674017. The reversal of 673991 is 199376.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 673991 - 2¹⁰ = 672967 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (673921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 336995 + 336996.

It is an arithmetic number, because the mean of its divisors is an integer number (336996).

2⁶⁷³⁹⁹¹ is an apocalyptic number.

673991 is a deficient number, since it is larger than the sum of its proper divisors (1).

673991 is an equidigital number, since it uses as much as digits as its factorization.

673991 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 673991 is about 820.9695487654. The cubic root of 673991 is about 87.6768016992.

The spelling of 673991 in words is "six hundred seventy-three thousand, nine hundred ninety-one".