81485564072 has 64 divisors (see below), whose sum is σ = 169101777600. Its totient is φ = 36501834240.

The previous prime is 81485564029. The next prime is 81485564087. The reversal of 81485564072 is 27046558418.

It is a self number, because there is not a number n which added to its sum of digits gives 81485564072.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2973698 + ... + 3000974.

It is an arithmetic number, because the mean of its divisors is an integer number (2642215275).

Almost surely, 2^81485564072 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 81485564072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84550888800).

81485564072 is an abundant number, since it is smaller than the sum of its proper divisors (87616213528).

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

81485564072 is a wasteful number, since it uses less digits than its factorization.

81485564072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27786 (or 27782 counting only the distinct ones).

The product of its (nonzero) digits is 2150400, while the sum is 50.

The spelling of 81485564072 in words is "eighty-one billion, four hundred eighty-five million, five hundred sixty-four thousand, seventy-two".