72319609 has 4 divisors (see below), whose sum is σ = 72694516. Its totient is φ = 71944704.

The previous prime is 72319607. The next prime is 72319633. The reversal of 72319609 is 90691327.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90691327 = 809 ⋅112103.

It can be written as a sum of positive squares in 2 ways, for example, as 52606009 + 19713600 = 7253^2 + 4440^2 .

It is a cyclic number.

It is not a de Polignac number, because 72319609 - 2¹ = 72319607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72319601) 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, 187164 + ... + 187549.

It is an arithmetic number, because the mean of its divisors is an integer number (18173629).

Almost surely, 2^72319609 is an apocalyptic number.

It is an amenable number.

72319609 is a deficient number, since it is larger than the sum of its proper divisors (374907).

72319609 is a wasteful number, since it uses less digits than its factorization.

72319609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374906.

The product of its (nonzero) digits is 20412, while the sum is 37.

The square root of 72319609 is about 8504.0936612904. The cubic root of 72319609 is about 416.6314240770.

The spelling of 72319609 in words is "seventy-two million, three hundred nineteen thousand, six hundred nine".