68566681 has 8 divisors (see below), whose sum is σ = 69440840. Its totient is φ = 67696128.

The previous prime is 68566651. The next prime is 68566691. The reversal of 68566681 is 18666586.

It is the 3381-st star number.

It can be written as a sum of positive squares in 4 ways, for example, as 8643600 + 59923081 = 2940^2 + 7741^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 68566681 - 2¹³ = 68558489 is a prime.

It is a super-2 number, since 2×68566681² = 9402779486711522, which contains 22 as substring.

It is the 8281-st Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68566651) by changing a digit.

It is a nontrivial repunit in base 8280.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68275 + ... + 69271.

It is an arithmetic number, because the mean of its divisors is an integer number (8680105).

Almost surely, 2^68566681 is an apocalyptic number.

It is an amenable number.

68566681 is a deficient number, since it is larger than the sum of its proper divisors (874159).

68566681 is an equidigital number, since it uses as much as digits as its factorization.

68566681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1803.

The product of its digits is 414720, while the sum is 46.

The square root of 68566681 is about 8280.5000452871. The cubic root of 68566681 is about 409.2961968706.

The spelling of 68566681 in words is "sixty-eight million, five hundred sixty-six thousand, six hundred eighty-one".