71725809 has 4 divisors (see below), whose sum is σ = 95634416. Its totient is φ = 47817204.

The previous prime is 71725793. The next prime is 71725811. The reversal of 71725809 is 90852717.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90852717 = 3 ⋅30284239.

It is not a de Polignac number, because 71725809 - 2⁴ = 71725793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71725859) 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 3 ways as a sum of consecutive naturals, for example, 11954299 + ... + 11954304.

It is an arithmetic number, because the mean of its divisors is an integer number (23908604).

Almost surely, 2^71725809 is an apocalyptic number.

It is an amenable number.

71725809 is a deficient number, since it is larger than the sum of its proper divisors (23908607).

71725809 is a wasteful number, since it uses less digits than its factorization.

71725809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23908606.

The product of its (nonzero) digits is 35280, while the sum is 39.

The square root of 71725809 is about 8469.1091030875. The cubic root of 71725809 is about 415.4879999894.

The spelling of 71725809 in words is "seventy-one million, seven hundred twenty-five thousand, eight hundred nine".