81105444 has 36 divisors (see below), whose sum is σ = 234305344. Its totient is φ = 23172912.

The previous prime is 81105407. The next prime is 81105457. The reversal of 81105444 is 44450118.

It is a happy number.

81105444 is a `hidden beast` number, since 8 + 110 + 544 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 160672 + ... + 161175.

Almost surely, 2^81105444 is an apocalyptic number.

81105444 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

81105444 is an abundant number, since it is smaller than the sum of its proper divisors (153199900).

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

81105444 is a wasteful number, since it uses less digits than its factorization.

81105444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321864 (or 321859 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The square root of 81105444 is about 9005.8560947863. The cubic root of 81105444 is about 432.8625385261.

The spelling of 81105444 in words is "eighty-one million, one hundred five thousand, four hundred forty-four".