72725809 has 4 divisors (see below), whose sum is σ = 78320116. Its totient is φ = 67131504.

The previous prime is 72725803. The next prime is 72725827. The reversal of 72725809 is 90852727.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5895184 + 66830625 = 2428^2 + 8175^2 .

It is a cyclic number.

It is not a de Polignac number, because 72725809 - 2³ = 72725801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72725801) 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, 2797134 + ... + 2797159.

It is an arithmetic number, because the mean of its divisors is an integer number (19580029).

Almost surely, 2^72725809 is an apocalyptic number.

It is an amenable number.

72725809 is a deficient number, since it is larger than the sum of its proper divisors (5594307).

72725809 is a wasteful number, since it uses less digits than its factorization.

72725809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5594306.

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 72725809 is about 8527.9428351743. The cubic root of 72725809 is about 417.4100041477.

The spelling of 72725809 in words is "seventy-two million, seven hundred twenty-five thousand, eight hundred nine".