71209 has 2 divisors, whose sum is σ = 71210. Its totient is φ = 71208.

The previous prime is 71191. The next prime is 71233. The reversal of 71209 is 90217.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38809 + 32400 = 197^2 + 180^2 .

It is an emirp because it is prime and its reverse (90217) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71209 - 2⁷ = 71081 is a prime.

It is not a weakly prime, because it can be changed into another prime (71249) 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, 35604 + 35605.

It is an arithmetic number, because the mean of its divisors is an integer number (35605).

2⁷¹²⁰⁹ is an apocalyptic number.

It is an amenable number.

71209 is a deficient number, since it is larger than the sum of its proper divisors (1).

71209 is an equidigital number, since it uses as much as digits as its factorization.

71209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 126, while the sum is 19.

The square root of 71209 is about 266.8501452126. The cubic root of 71209 is about 41.4487682509.

The spelling of 71209 in words is "seventy-one thousand, two hundred nine".