81182736 has 100 divisors (see below), whose sum is σ = 241459372. Its totient is φ = 26313984.

The previous prime is 81182723. The next prime is 81182767. The reversal of 81182736 is 63728118.

It is a Cunningham number, because it is equal to 433³-1.

It can be written as a sum of positive squares in 2 ways, for example, as 53934336 + 27248400 = 7344^2 + 5220^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 81182736.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 47106 + ... + 48798.

Almost surely, 2^81182736 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81182736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120729686).

81182736 is an abundant number, since it is smaller than the sum of its proper divisors (160276636).

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

81182736 is a wasteful number, since it uses less digits than its factorization.

81182736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1750 (or 1735 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 81182736 is about 9010.1462807215. The cubic root of 81182736 is about 432.9999982221. Note that the first 5 decimals are identical.

It can be divided in two parts, 81182 and 736, that added together give a palindrome (81918).

The spelling of 81182736 in words is "eighty-one million, one hundred eighty-two thousand, seven hundred thirty-six".