66968161 has 8 divisors (see below), whose sum is σ = 72432360. Its totient is φ = 61548672.

The previous prime is 66968159. The next prime is 66968171. The reversal of 66968161 is 16186966.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2085136 + 64883025 = 1444^2 + 8055^2 .

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 66968161 - 2¹ = 66968159 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66968131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8026 + ... + 14083.

It is an arithmetic number, because the mean of its divisors is an integer number (9054045).

Almost surely, 2^66968161 is an apocalyptic number.

It is an amenable number.

66968161 is a deficient number, since it is larger than the sum of its proper divisors (5464199).

66968161 is a wasteful number, since it uses less digits than its factorization.

66968161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22355.

The product of its digits is 93312, while the sum is 43.

The square root of 66968161 is about 8183.4076642924. The cubic root of 66968161 is about 406.0904637165.

The spelling of 66968161 in words is "sixty-six million, nine hundred sixty-eight thousand, one hundred sixty-one".