81544041 has 12 divisors (see below), whose sum is σ = 120969732. Its totient is φ = 52893216.

The previous prime is 81543989. The next prime is 81544061. The reversal of 81544041 is 14044518.

It is a happy number.

81544041 is a `hidden beast` number, since 81 + 544 + 0 + 41 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 77528025 + 4016016 = 8805^2 + 2004^2 .

It is not a de Polignac number, because 81544041 - 2⁶ = 81543977 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81543996 and 81544014.

It is not an unprimeable number, because it can be changed into a prime (81544061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 122106 + ... + 122771.

It is an arithmetic number, because the mean of its divisors is an integer number (10080811).

Almost surely, 2^81544041 is an apocalyptic number.

It is an amenable number.

81544041 is a deficient number, since it is larger than the sum of its proper divisors (39425691).

81544041 is a wasteful number, since it uses less digits than its factorization.

81544041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244920 (or 244917 counting only the distinct ones).

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

The square root of 81544041 is about 9030.1739185909. The cubic root of 81544041 is about 433.6414053207.

Adding to 81544041 its reverse (14044518), we get a palindrome (95588559).

The spelling of 81544041 in words is "eighty-one million, five hundred forty-four thousand, forty-one".