66188197 has 2 divisors, whose sum is σ = 66188198. Its totient is φ = 66188196.

The previous prime is 66188183. The next prime is 66188201. The reversal of 66188197 is 79188166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51854401 + 14333796 = 7201^2 + 3786^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66188197 is a prime.

It is a super-2 number, since 2×66188197² = 8761754844221618, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66188107) 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, 33094098 + 33094099.

It is an arithmetic number, because the mean of its divisors is an integer number (33094099).

Almost surely, 2^66188197 is an apocalyptic number.

It is an amenable number.

66188197 is a deficient number, since it is larger than the sum of its proper divisors (1).

66188197 is an equidigital number, since it uses as much as digits as its factorization.

66188197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 46.

The square root of 66188197 is about 8135.6128841041. The cubic root of 66188197 is about 404.5077533232.

The spelling of 66188197 in words is "sixty-six million, one hundred eighty-eight thousand, one hundred ninety-seven".