71709409 has 2 divisors, whose sum is σ = 71709410. Its totient is φ = 71709408.

The previous prime is 71709397. The next prime is 71709413. The reversal of 71709409 is 90490717.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50979600 + 20729809 = 7140^2 + 4553^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71709409 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (71709419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35854704 + 35854705.

It is an arithmetic number, because the mean of its divisors is an integer number (35854705).

Almost surely, 2^71709409 is an apocalyptic number.

It is an amenable number.

71709409 is a deficient number, since it is larger than the sum of its proper divisors (1).

71709409 is an equidigital number, since it uses as much as digits as its factorization.

71709409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15876, while the sum is 37.

The square root of 71709409 is about 8468.1408231087. The cubic root of 71709409 is about 415.4563306703.

The spelling of 71709409 in words is "seventy-one million, seven hundred nine thousand, four hundred nine".