66888197 has 2 divisors, whose sum is σ = 66888198. Its totient is φ = 66888196.

The previous prime is 66888169. The next prime is 66888223. The reversal of 66888197 is 79188866.

66888197 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43375396 + 23512801 = 6586^2 + 4849^2 .

It is a cyclic number.

It is not a de Polignac number, because 66888197 - 2¹² = 66884101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66888137) by changing a digit.

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 as a sum of consecutive naturals, namely, 33444098 + 33444099.

It is an arithmetic number, because the mean of its divisors is an integer number (33444099).

Almost surely, 2^66888197 is an apocalyptic number.

It is an amenable number.

66888197 is a deficient number, since it is larger than the sum of its proper divisors (1).

66888197 is an equidigital number, since it uses as much as digits as its factorization.

66888197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1161216, while the sum is 53.

The square root of 66888197 is about 8178.5204652186. The cubic root of 66888197 is about 405.9287672193.

The spelling of 66888197 in words is "sixty-six million, eight hundred eighty-eight thousand, one hundred ninety-seven".