66358109 has 2 divisors, whose sum is σ = 66358110. Its totient is φ = 66358108.

The previous prime is 66358099. The next prime is 66358141. The reversal of 66358109 is 90185366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43270084 + 23088025 = 6578^2 + 4805^2 .

It is a cyclic number.

It is not a de Polignac number, because 66358109 - 2⁴ = 66358093 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 (66358169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33179054 + 33179055.

It is an arithmetic number, because the mean of its divisors is an integer number (33179055).

Almost surely, 2^66358109 is an apocalyptic number.

It is an amenable number.

66358109 is a deficient number, since it is larger than the sum of its proper divisors (1).

66358109 is an equidigital number, since it uses as much as digits as its factorization.

66358109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 66358109 is about 8146.0486740505. The cubic root of 66358109 is about 404.8535954081.

The spelling of 66358109 in words is "sixty-six million, three hundred fifty-eight thousand, one hundred nine".