72072009 has 12 divisors (see below), whose sum is σ = 106319616. Its totient is φ = 47025432.

The previous prime is 72071983. The next prime is 72072017. The reversal of 72072009 is 90027027.

It is not a de Polignac number, because 72072009 - 2²¹ = 69974857 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72072019) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 84769 + ... + 85614.

It is an arithmetic number, because the mean of its divisors is an integer number (8859968).

Almost surely, 2^72072009 is an apocalyptic number.

It is an amenable number.

72072009 is a deficient number, since it is larger than the sum of its proper divisors (34247607).

72072009 is a wasteful number, since it uses less digits than its factorization.

72072009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170436 (or 170433 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 27.

The square root of 72072009 is about 8489.5234848606. The cubic root of 72072009 is about 416.1554079893.

It can be divided in two parts, 7207 and 2009, that added together give a square (9216 = 96²).

The spelling of 72072009 in words is "seventy-two million, seventy-two thousand, nine".