66173897 has 2 divisors, whose sum is σ = 66173898. Its totient is φ = 66173896.

The previous prime is 66173879. The next prime is 66173909. The reversal of 66173897 is 79837166.

Together with previous prime (66173879) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62425801 + 3748096 = 7901^2 + 1936^2 .

It is a cyclic number.

It is not a de Polignac number, because 66173897 - 2⁸ = 66173641 is a prime.

It is not a weakly prime, because it can be changed into another prime (66173857) 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, 33086948 + 33086949.

It is an arithmetic number, because the mean of its divisors is an integer number (33086949).

Almost surely, 2^66173897 is an apocalyptic number.

It is an amenable number.

66173897 is a deficient number, since it is larger than the sum of its proper divisors (1).

66173897 is an equidigital number, since it uses as much as digits as its factorization.

66173897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 381024, while the sum is 47.

The square root of 66173897 is about 8134.7339845873. The cubic root of 66173897 is about 404.4786198434.

The spelling of 66173897 in words is "sixty-six million, one hundred seventy-three thousand, eight hundred ninety-seven".