81804272 has 80 divisors (see below), whose sum is σ = 192844800. Its totient is φ = 33131520.

The previous prime is 81804269. The next prime is 81804287. The reversal of 81804272 is 27240818.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56129 + ... + 57567.

It is an arithmetic number, because the mean of its divisors is an integer number (2410560).

Almost surely, 2^81804272 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 81804272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96422400).

81804272 is an abundant number, since it is smaller than the sum of its proper divisors (111040528).

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

81804272 is a wasteful number, since it uses less digits than its factorization.

81804272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1494 (or 1488 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 81804272 is about 9044.5714105202. The cubic root of 81804272 is about 434.1022078717.

The spelling of 81804272 in words is "eighty-one million, eight hundred four thousand, two hundred seventy-two".