72000009 has 20 divisors (see below), whose sum is σ = 109169104. Its totient is φ = 47280024.

The previous prime is 72000007. The next prime is 72000053. The reversal of 72000009 is 90000027.

It is not a de Polignac number, because 72000009 - 2¹ = 72000007 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 71999955 and 72000000.

It is not an unprimeable number, because it can be changed into a prime (72000007) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1207 + ... + 12060.

Almost surely, 2^72000009 is an apocalyptic number.

It is an amenable number.

72000009 is a deficient number, since it is larger than the sum of its proper divisors (37169095).

72000009 is a wasteful number, since it uses less digits than its factorization.

72000009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13346 (or 13337 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 18.

The square root of 72000009 is about 8485.2819045686. The cubic root of 72000009 is about 416.0167819444.

Adding to 72000009 its sum of digits (18), we get a palindrome (72000027).

The spelling of 72000009 in words is "seventy-two million, nine", and thus it is an aban number and an uban number.