81043634518 has 16 divisors (see below), whose sum is σ = 151562121984. Its totient is φ = 31575441960.

The previous prime is 81043634479. The next prime is 81043634519. The reversal of 81043634518 is 81543634018.

It is a super-2 number, since 2×81043634518² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81043634519) 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, 263128530 + ... + 263128837.

It is an arithmetic number, because the mean of its divisors is an integer number (9472632624).

Almost surely, 2^81043634518 is an apocalyptic number.

81043634518 is a deficient number, since it is larger than the sum of its proper divisors (70518487466).

81043634518 is a wasteful number, since it uses less digits than its factorization.

81043634518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 526257387.

The product of its (nonzero) digits is 276480, while the sum is 43.

The spelling of 81043634518 in words is "eighty-one billion, forty-three million, six hundred thirty-four thousand, five hundred eighteen".