81105216 has 56 divisors (see below), whose sum is σ = 219846144. Its totient is φ = 26373120.

The previous prime is 81105209. The next prime is 81105223. The reversal of 81105216 is 61250118.

It is an interprime number because it is at equal distance from previous prime (81105209) and next prime (81105223).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2721 + ... + 13023.

It is an arithmetic number, because the mean of its divisors is an integer number (3925824).

Almost surely, 2^81105216 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 81105216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109923072).

81105216 is an abundant number, since it is smaller than the sum of its proper divisors (138740928).

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

81105216 is a wasteful number, since it uses less digits than its factorization.

81105216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10359 (or 10349 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 24.

The square root of 81105216 is about 9005.8434363473. The cubic root of 81105216 is about 432.8621329111.

The spelling of 81105216 in words is "eighty-one million, one hundred five thousand, two hundred sixteen".