673681 has 4 divisors (see below), whose sum is σ = 689392. Its totient is φ = 657972.

The previous prime is 673669. The next prime is 673747. The reversal of 673681 is 186376.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 673681 - 2⁵ = 673649 is a prime.

It is a super-2 number, since 2×673681² = 907692179522, which contains 22 as substring.

It is a Duffinian number.

673681 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (673381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7791 + ... + 7876.

It is an arithmetic number, because the mean of its divisors is an integer number (172348).

2⁶⁷³⁶⁸¹ is an apocalyptic number.

It is an amenable number.

673681 is a deficient number, since it is larger than the sum of its proper divisors (15711).

673681 is a wasteful number, since it uses less digits than its factorization.

673681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15710.

The product of its digits is 6048, while the sum is 31.

The square root of 673681 is about 820.7807258946. The cubic root of 673681 is about 87.6633574164.

The spelling of 673681 in words is "six hundred seventy-three thousand, six hundred eighty-one".