72432209 has 4 divisors (see below), whose sum is σ = 73073316. Its totient is φ = 71791104.

The previous prime is 72432203. The next prime is 72432247. The reversal of 72432209 is 90223427.

It is a happy number.

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 16974400 + 55457809 = 4120^2 + 7447^2 .

It is a cyclic number.

It is not a de Polignac number, because 72432209 - 2¹² = 72428113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72432203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 320384 + ... + 320609.

It is an arithmetic number, because the mean of its divisors is an integer number (18268329).

Almost surely, 2^72432209 is an apocalyptic number.

It is an amenable number.

72432209 is a deficient number, since it is larger than the sum of its proper divisors (641107).

72432209 is a wasteful number, since it uses less digits than its factorization.

72432209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641106.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 72432209 is about 8510.7114273720. The cubic root of 72432209 is about 416.8475405296.

The spelling of 72432209 in words is "seventy-two million, four hundred thirty-two thousand, two hundred nine".