68306681 has 4 divisors (see below), whose sum is σ = 68474100. Its totient is φ = 68139264.

The previous prime is 68306677. The next prime is 68306683. The reversal of 68306681 is 18660386.

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 27920656 + 40386025 = 5284^2 + 6355^2 .

It is a cyclic number.

It is not a de Polignac number, because 68306681 - 2² = 68306677 is a prime.

It is a super-2 number, since 2×68306681² = 9331605338471522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68306683) 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, 83096 + ... + 83913.

It is an arithmetic number, because the mean of its divisors is an integer number (17118525).

Almost surely, 2^68306681 is an apocalyptic number.

It is an amenable number.

68306681 is a deficient number, since it is larger than the sum of its proper divisors (167419).

68306681 is a wasteful number, since it uses less digits than its factorization.

68306681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167418.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 68306681 is about 8264.7855991550. The cubic root of 68306681 is about 408.7782008493.

The spelling of 68306681 in words is "sixty-eight million, three hundred six thousand, six hundred eighty-one".