66688073 has 2 divisors, whose sum is σ = 66688074. Its totient is φ = 66688072.

The previous prime is 66688057. The next prime is 66688103. The reversal of 66688073 is 37088666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53993104 + 12694969 = 7348^2 + 3563^2 .

It is a cyclic number.

It is not a de Polignac number, because 66688073 - 2⁴ = 66688057 is a prime.

It is a zygodrome in base 3.

It is not a weakly prime, because it can be changed into another prime (66688003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33344036 + 33344037.

It is an arithmetic number, because the mean of its divisors is an integer number (33344037).

Almost surely, 2^66688073 is an apocalyptic number.

It is an amenable number.

66688073 is a deficient number, since it is larger than the sum of its proper divisors (1).

66688073 is an equidigital number, since it uses as much as digits as its factorization.

66688073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 290304, while the sum is 44.

The square root of 66688073 is about 8166.2765689144. The cubic root of 66688073 is about 405.5235276084.

It can be divided in two parts, 6668 and 8073, that added together give a palindrome (14741).

The spelling of 66688073 in words is "sixty-six million, six hundred eighty-eight thousand, seventy-three".