67681 has 4 divisors (see below), whose sum is σ = 69012. Its totient is φ = 66352.

The previous prime is 67679. The next prime is 67699. The reversal of 67681 is 18676.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 46656 + 21025 = 216^2 + 145^2 .

It is a cyclic number.

It is not a de Polignac number, because 67681 - 2¹ = 67679 is a prime.

It is a super-2 number, since 2×67681² = 9161435522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67601) 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 in 3 ways as a sum of consecutive naturals, for example, 586 + ... + 691.

It is an arithmetic number, because the mean of its divisors is an integer number (17253).

2⁶⁷⁶⁸¹ is an apocalyptic number.

It is an amenable number.

67681 is a deficient number, since it is larger than the sum of its proper divisors (1331).

67681 is a wasteful number, since it uses less digits than its factorization.

67681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1330.

The product of its digits is 2016, while the sum is 28.

The square root of 67681 is about 260.1557225971. The cubic root of 67681 is about 40.7526250708.

It can be divided in two parts, 676 and 81, that multiplied together give a square (54756 = 234²).

The spelling of 67681 in words is "sixty-seven thousand, six hundred eighty-one".