81105408 has 80 divisors (see below), whose sum is σ = 240118560. Its totient is φ = 27030528.

The previous prime is 81105407. The next prime is 81105457. The reversal of 81105408 is 80450118.

81105408 is a `hidden beast` number, since 8 + 110 + 540 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (81105403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10891 + ... + 16757.

It is an arithmetic number, because the mean of its divisors is an integer number (3001482).

Almost surely, 2^81105408 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 81105408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120059280).

81105408 is an abundant number, since it is smaller than the sum of its proper divisors (159013152).

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

81105408 is an equidigital number, since it uses as much as digits as its factorization.

81105408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5894 (or 5872 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 81105408 is about 9005.8540960866. The cubic root of 81105408 is about 432.8624744816.

The spelling of 81105408 in words is "eighty-one million, one hundred five thousand, four hundred eight".