71043209 has 2 divisors, whose sum is σ = 71043210. Its totient is φ = 71043208.

The previous prime is 71043191. The next prime is 71043211. The reversal of 71043209 is 90234017.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61277584 + 9765625 = 7828^2 + 3125^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71043209 is a prime.

Together with 71043211, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (71043409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35521604 + 35521605.

It is an arithmetic number, because the mean of its divisors is an integer number (35521605).

Almost surely, 2^71043209 is an apocalyptic number.

It is an amenable number.

71043209 is a deficient number, since it is larger than the sum of its proper divisors (1).

71043209 is an equidigital number, since it uses as much as digits as its factorization.

71043209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 71043209 is about 8428.7133656330. The cubic root of 71043209 is about 414.1657581868.

The spelling of 71043209 in words is "seventy-one million, forty-three thousand, two hundred nine".