72073009 has 4 divisors (see below), whose sum is σ = 72126580. Its totient is φ = 72019440.

The previous prime is 72072997. The next prime is 72073021. The reversal of 72073009 is 90037027.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (72072997) and next prime (72073021).

It can be written as a sum of positive squares in 2 ways, for example, as 10497600 + 61575409 = 3240^2 + 7847^2 .

It is a cyclic number.

It is not a de Polignac number, because 72073009 - 2⁵ = 72072977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72073609) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24714 + ... + 27475.

It is an arithmetic number, because the mean of its divisors is an integer number (18031645).

Almost surely, 2^72073009 is an apocalyptic number.

It is an amenable number.

72073009 is a deficient number, since it is larger than the sum of its proper divisors (53571).

72073009 is a wasteful number, since it uses less digits than its factorization.

72073009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53570.

The product of its (nonzero) digits is 2646, while the sum is 28.

The square root of 72073009 is about 8489.5823807770. The cubic root of 72073009 is about 416.1573327009.

The spelling of 72073009 in words is "seventy-two million, seventy-three thousand, nine".