66944161 has 2 divisors, whose sum is σ = 66944162. Its totient is φ = 66944160.

The previous prime is 66944149. The next prime is 66944167. The reversal of 66944161 is 16144966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66732561 + 211600 = 8169^2 + 460^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66944161 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66944161.

It is not a weakly prime, because it can be changed into another prime (66944167) 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 as a sum of consecutive naturals, namely, 33472080 + 33472081.

It is an arithmetic number, because the mean of its divisors is an integer number (33472081).

Almost surely, 2^66944161 is an apocalyptic number.

It is an amenable number.

66944161 is a deficient number, since it is larger than the sum of its proper divisors (1).

66944161 is an equidigital number, since it uses as much as digits as its factorization.

66944161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 37.

The square root of 66944161 is about 8181.9411510961. The cubic root of 66944161 is about 406.0419464535.

The spelling of 66944161 in words is "sixty-six million, nine hundred forty-four thousand, one hundred sixty-one".