66913109 has 2 divisors, whose sum is σ = 66913110. Its totient is φ = 66913108.

The previous prime is 66913103. The next prime is 66913111. The reversal of 66913109 is 90131966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63840100 + 3073009 = 7990^2 + 1753^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66913109 is a prime.

Together with 66913111, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66913103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33456554 + 33456555.

It is an arithmetic number, because the mean of its divisors is an integer number (33456555).

Almost surely, 2^66913109 is an apocalyptic number.

It is an amenable number.

66913109 is a deficient number, since it is larger than the sum of its proper divisors (1).

66913109 is an equidigital number, since it uses as much as digits as its factorization.

66913109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8748, while the sum is 35.

The square root of 66913109 is about 8180.0433372935. The cubic root of 66913109 is about 405.9791559910.

The spelling of 66913109 in words is "sixty-six million, nine hundred thirteen thousand, one hundred nine".