66994177 has 2 divisors, whose sum is σ = 66994178. Its totient is φ = 66994176.

The previous prime is 66994163. The next prime is 66994199. The reversal of 66994177 is 77149966.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55711296 + 11282881 = 7464^2 + 3359^2 .

It is a cyclic number.

It is not a de Polignac number, because 66994177 - 2⁷ = 66994049 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66994177.

It is not a weakly prime, because it can be changed into another prime (66994777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33497088 + 33497089.

It is an arithmetic number, because the mean of its divisors is an integer number (33497089).

It is a Proth number, since it is equal to 4089 ⋅ 2¹⁴ + 1 and 4089 < 2¹⁴.

Almost surely, 2^66994177 is an apocalyptic number.

It is an amenable number.

66994177 is a deficient number, since it is larger than the sum of its proper divisors (1).

66994177 is an equidigital number, since it uses as much as digits as its factorization.

66994177 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 571536, while the sum is 49.

The square root of 66994177 is about 8184.9970678064. The cubic root of 66994177 is about 406.1430433382.

The spelling of 66994177 in words is "sixty-six million, nine hundred ninety-four thousand, one hundred seventy-seven".