72856581 has 24 divisors (see below), whose sum is σ = 114063840. Its totient is φ = 41241312.

The previous prime is 72856561. The next prime is 72856607. The reversal of 72856581 is 18565827.

It is not a de Polignac number, because 72856581 - 2¹¹ = 72854533 is a prime.

It is a super-2 number, since 2×72856581² = 10616162790019122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72856561) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13750 + ... + 18296.

It is an arithmetic number, because the mean of its divisors is an integer number (4752660).

Almost surely, 2^72856581 is an apocalyptic number.

It is an amenable number.

72856581 is a deficient number, since it is larger than the sum of its proper divisors (41207259).

72856581 is a wasteful number, since it uses less digits than its factorization.

72856581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4673 (or 4666 counting only the distinct ones).

The product of its digits is 134400, while the sum is 42.

The square root of 72856581 is about 8535.6066568229. The cubic root of 72856581 is about 417.6600431035.

It can be divided in two parts, 72856 and 581, that added together give a palindrome (73437).

The spelling of 72856581 in words is "seventy-two million, eight hundred fifty-six thousand, five hundred eighty-one".