66695081 has 2 divisors, whose sum is σ = 66695082. Its totient is φ = 66695080.

The previous prime is 66695071. The next prime is 66695089. The reversal of 66695081 is 18059666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64320400 + 2374681 = 8020^2 + 1541^2 .

It is a cyclic number.

It is not a de Polignac number, because 66695081 - 2⁶ = 66695017 is a prime.

It is a super-2 number, since 2×66695081² = 8896467659193122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (66695089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33347540 + 33347541.

It is an arithmetic number, because the mean of its divisors is an integer number (33347541).

Almost surely, 2^66695081 is an apocalyptic number.

It is an amenable number.

66695081 is a deficient number, since it is larger than the sum of its proper divisors (1).

66695081 is an equidigital number, since it uses as much as digits as its factorization.

66695081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 41.

The square root of 66695081 is about 8166.7056393628. The cubic root of 66695081 is about 405.5377320941.

The spelling of 66695081 in words is "sixty-six million, six hundred ninety-five thousand, eighty-one".