81817122 has 32 divisors (see below), whose sum is σ = 170532864. Its totient is φ = 26139600.

The previous prime is 81817121. The next prime is 81817147. The reversal of 81817122 is 22171818.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 81817122.

It is not an unprimeable number, because it can be changed into a prime (81817121) 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 in 15 ways as a sum of consecutive naturals, for example, 17847 + ... + 21957.

It is an arithmetic number, because the mean of its divisors is an integer number (5329152).

Almost surely, 2^81817122 is an apocalyptic number.

81817122 is an abundant number, since it is smaller than the sum of its proper divisors (88715742).

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

81817122 is a wasteful number, since it uses less digits than its factorization.

81817122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4254.

The product of its digits is 1792, while the sum is 30.

The square root of 81817122 is about 9045.2817534889. The cubic root of 81817122 is about 434.1249366004.

The spelling of 81817122 in words is "eighty-one million, eight hundred seventeen thousand, one hundred twenty-two".