72397700209 has 4 divisors (see below), whose sum is σ = 74894172660. Its totient is φ = 69901227760.

The previous prime is 72397700189. The next prime is 72397700273. The reversal of 72397700209 is 90200779327.

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 49094151184 + 23303549025 = 221572^2 + 152655^2 .

It is a cyclic number.

It is not a de Polignac number, because 72397700209 - 2⁹ = 72397699697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72397700509) 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, 1248236182 + ... + 1248236239.

It is an arithmetic number, because the mean of its divisors is an integer number (18723543165).

Almost surely, 2^72397700209 is an apocalyptic number.

It is an amenable number.

72397700209 is a deficient number, since it is larger than the sum of its proper divisors (2496472451).

72397700209 is a wasteful number, since it uses less digits than its factorization.

72397700209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2496472450.

The product of its (nonzero) digits is 333396, while the sum is 46.

The spelling of 72397700209 in words is "seventy-two billion, three hundred ninety-seven million, seven hundred thousand, two hundred nine".