71530809 has 16 divisors (see below), whose sum is σ = 109148160. Its totient is φ = 40818960.

The previous prime is 71530793. The next prime is 71530831. The reversal of 71530809 is 90803517.

It is not a de Polignac number, because 71530809 - 2⁴ = 71530793 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 71530809.

It is not an unprimeable number, because it can be changed into a prime (71530859) 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 in 15 ways as a sum of consecutive naturals, for example, 17262 + ... + 21000.

It is an arithmetic number, because the mean of its divisors is an integer number (6821760).

Almost surely, 2^71530809 is an apocalyptic number.

It is an amenable number.

71530809 is a deficient number, since it is larger than the sum of its proper divisors (37617351).

71530809 is a wasteful number, since it uses less digits than its factorization.

71530809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4660.

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 71530809 is about 8457.5888407985. The cubic root of 71530809 is about 415.1111310258. Note that the first 4 decimals are identical.

The spelling of 71530809 in words is "seventy-one million, five hundred thirty thousand, eight hundred nine".