72005660665 has 8 divisors (see below), whose sum is σ = 86506921728. Its totient is φ = 57537775920.

The previous prime is 72005660659. The next prime is 72005660711. The reversal of 72005660665 is 56606650027.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 72005660665 - 2¹⁹ = 72005136377 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8339331 + ... + 8347960.

It is an arithmetic number, because the mean of its divisors is an integer number (10813365216).

Almost surely, 2^72005660665 is an apocalyptic number.

It is an amenable number.

72005660665 is a deficient number, since it is larger than the sum of its proper divisors (14501261063).

72005660665 is a wasteful number, since it uses less digits than its factorization.

72005660665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16688159.

The product of its (nonzero) digits is 453600, while the sum is 43.

The spelling of 72005660665 in words is "seventy-two billion, five million, six hundred sixty thousand, six hundred sixty-five".