81443004885 has 96 divisors (see below), whose sum is σ = 156823070976. Its totient is φ = 39093648000.

The previous prime is 81443004859. The next prime is 81443004889. The reversal of 81443004885 is 58840034418.

It is not a de Polignac number, because 81443004885 - 2¹² = 81443000789 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 81443004885.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81443004889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6042664 + ... + 6056126.

It is an arithmetic number, because the mean of its divisors is an integer number (1633573656).

Almost surely, 2^81443004885 is an apocalyptic number.

It is an amenable number.

81443004885 is a deficient number, since it is larger than the sum of its proper divisors (75380066091).

81443004885 is a wasteful number, since it uses less digits than its factorization.

81443004885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13608 (or 13583 counting only the distinct ones).

The product of its (nonzero) digits is 491520, while the sum is 45.

The spelling of 81443004885 in words is "eighty-one billion, four hundred forty-three million, four thousand, eight hundred eighty-five".