81818224 has 10 divisors (see below), whose sum is σ = 158522840. Its totient is φ = 40909104.

The previous prime is 81818197. The next prime is 81818227. The reversal of 81818224 is 42281818.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 81818224.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81818227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2556804 + ... + 2556835.

It is an arithmetic number, because the mean of its divisors is an integer number (15852284).

Almost surely, 2^81818224 is an apocalyptic number.

It is an amenable number.

81818224 is a deficient number, since it is larger than the sum of its proper divisors (76704616).

81818224 is a wasteful number, since it uses less digits than its factorization.

81818224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5113647 (or 5113641 counting only the distinct ones).

The product of its digits is 8192, while the sum is 34.

The square root of 81818224 is about 9045.3426690203. The cubic root of 81818224 is about 434.1268856771.

The spelling of 81818224 in words is "eighty-one million, eight hundred eighteen thousand, two hundred twenty-four".