81856272 has 20 divisors (see below), whose sum is σ = 211462160. Its totient is φ = 27285408.

The previous prime is 81856231. The next prime is 81856273. The reversal of 81856272 is 27265818.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 81856272.

It is not an unprimeable number, because it can be changed into a prime (81856273) 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, 852622 + ... + 852717.

It is an arithmetic number, because the mean of its divisors is an integer number (10573108).

Almost surely, 2^81856272 is an apocalyptic number.

It is an amenable number.

81856272 is an abundant number, since it is smaller than the sum of its proper divisors (129605888).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81856272 is a wasteful number, since it uses less digits than its factorization.

81856272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1705350 (or 1705344 counting only the distinct ones).

The product of its digits is 53760, while the sum is 39.

The square root of 81856272 is about 9047.4456063576. The cubic root of 81856272 is about 434.1941693832.

It can be divided in two parts, 81856 and 272, that added together give a palindrome (82128).

The spelling of 81856272 in words is "eighty-one million, eight hundred fifty-six thousand, two hundred seventy-two".