71066909 has 2 divisors, whose sum is σ = 71066910. Its totient is φ = 71066908.

The previous prime is 71066903. The next prime is 71066959. The reversal of 71066909 is 90966017.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63520900 + 7546009 = 7970^2 + 2747^2 .

It is a cyclic number.

It is not a de Polignac number, because 71066909 - 2⁴ = 71066893 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 (71066903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35533454 + 35533455.

It is an arithmetic number, because the mean of its divisors is an integer number (35533455).

Almost surely, 2^71066909 is an apocalyptic number.

It is an amenable number.

71066909 is a deficient number, since it is larger than the sum of its proper divisors (1).

71066909 is an equidigital number, since it uses as much as digits as its factorization.

71066909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20412, while the sum is 38.

The square root of 71066909 is about 8430.1191569277. The cubic root of 71066909 is about 414.2118082705.

The spelling of 71066909 in words is "seventy-one million, sixty-six thousand, nine hundred nine".