72856055021 has 8 divisors (see below), whose sum is σ = 73297457688. Its totient is φ = 72415080000.

The previous prime is 72856055017. The next prime is 72856055029. The reversal of 72856055021 is 12055065827.

It can be written as a sum of positive squares in 4 ways, for example, as 90992521 + 72765062500 = 9539^2 + 269750^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 72856055021 - 2² = 72856055017 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72856055021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72856055029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 238211 + ... + 449951.

It is an arithmetic number, because the mean of its divisors is an integer number (9162182211).

Almost surely, 2^72856055021 is an apocalyptic number.

It is an amenable number.

72856055021 is a deficient number, since it is larger than the sum of its proper divisors (441402667).

72856055021 is a wasteful number, since it uses less digits than its factorization.

72856055021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213823.

The product of its (nonzero) digits is 168000, while the sum is 41.

The spelling of 72856055021 in words is "seventy-two billion, eight hundred fifty-six million, fifty-five thousand, twenty-one".