66166729 has 2 divisors, whose sum is σ = 66166730. Its totient is φ = 66166728.

The previous prime is 66166691. The next prime is 66166733. The reversal of 66166729 is 92766166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51151104 + 15015625 = 7152^2 + 3875^2 .

It is a cyclic number.

It is not a de Polignac number, because 66166729 - 2¹⁹ = 65642441 is a prime.

It is not a weakly prime, because it can be changed into another prime (66166739) 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, 33083364 + 33083365.

It is an arithmetic number, because the mean of its divisors is an integer number (33083365).

Almost surely, 2^66166729 is an apocalyptic number.

It is an amenable number.

66166729 is a deficient number, since it is larger than the sum of its proper divisors (1).

66166729 is an equidigital number, since it uses as much as digits as its factorization.

66166729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 43.

The square root of 66166729 is about 8134.2933927908. The cubic root of 66166729 is about 404.4640148528.

The spelling of 66166729 in words is "sixty-six million, one hundred sixty-six thousand, seven hundred twenty-nine".