81541724918 has 16 divisors (see below), whose sum is σ = 129816555120. Its totient is φ = 38280988416.

The previous prime is 81541724917. The next prime is 81541724921. The reversal of 81541724918 is 81942714518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81541724917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2847671 + ... + 2876162.

It is an arithmetic number, because the mean of its divisors is an integer number (8113534695).

Almost surely, 2^81541724918 is an apocalyptic number.

81541724918 is a deficient number, since it is larger than the sum of its proper divisors (48274830202).

81541724918 is a wasteful number, since it uses less digits than its factorization.

81541724918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5724271.

The product of its digits is 645120, while the sum is 50.

The spelling of 81541724918 in words is "eighty-one billion, five hundred forty-one million, seven hundred twenty-four thousand, nine hundred eighteen".