66543173 has 2 divisors, whose sum is σ = 66543174. Its totient is φ = 66543172.

The previous prime is 66543167. The next prime is 66543179. The reversal of 66543173 is 37134566.

It is a balanced prime because it is at equal distance from previous prime (66543167) and next prime (66543179).

It can be written as a sum of positive squares in only one way, i.e., 60481729 + 6061444 = 7777^2 + 2462^2 .

It is a cyclic number.

It is not a de Polignac number, because 66543173 - 2⁴ = 66543157 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66543179) 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, 33271586 + 33271587.

It is an arithmetic number, because the mean of its divisors is an integer number (33271587).

Almost surely, 2^66543173 is an apocalyptic number.

It is an amenable number.

66543173 is a deficient number, since it is larger than the sum of its proper divisors (1).

66543173 is an equidigital number, since it uses as much as digits as its factorization.

66543173 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 35.

The square root of 66543173 is about 8157.3998921225. The cubic root of 66543173 is about 405.2296071407.

The spelling of 66543173 in words is "sixty-six million, five hundred forty-three thousand, one hundred seventy-three".