81041643500 has 192 divisors, whose sum is σ = 191615808384. Its totient is φ = 29832192000.

The previous prime is 81041643457. The next prime is 81041643533. The reversal of 81041643500 is 534614018.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 81285002 + ... + 81285998.

It is an arithmetic number, because the mean of its divisors is an integer number (997999002).

Almost surely, 2^81041643500 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 81041643500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95807904192).

81041643500 is an abundant number, since it is smaller than the sum of its proper divisors (110574164884).

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

81041643500 is a wasteful number, since it uses less digits than its factorization.

81041643500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1237 (or 1225 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The spelling of 81041643500 in words is "eighty-one billion, forty-one million, six hundred forty-three thousand, five hundred".