71311909 has 2 divisors, whose sum is σ = 71311910. Its totient is φ = 71311908.

The previous prime is 71311901. The next prime is 71311949. The reversal of 71311909 is 90911317.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71064900 + 247009 = 8430^2 + 497^2 .

It is a cyclic number.

It is not a de Polignac number, because 71311909 - 2³ = 71311901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71311901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35655954 + 35655955.

It is an arithmetic number, because the mean of its divisors is an integer number (35655955).

Almost surely, 2^71311909 is an apocalyptic number.

It is an amenable number.

71311909 is a deficient number, since it is larger than the sum of its proper divisors (1).

71311909 is an equidigital number, since it uses as much as digits as its factorization.

71311909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1701, while the sum is 31.

The square root of 71311909 is about 8444.6378844803. The cubic root of 71311909 is about 414.6872545749.

The spelling of 71311909 in words is "seventy-one million, three hundred eleven thousand, nine hundred nine".