81545090479520 has 192 divisors, whose sum is σ = 197695086220800. Its totient is φ = 31775352913920.

The previous prime is 81545090479453. The next prime is 81545090479537. The reversal of 81545090479520 is 2597409054518.

It is a self number, because there is not a number n which added to its sum of digits gives 81545090479520.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 1505411477 + ... + 1505465643.

It is an arithmetic number, because the mean of its divisors is an integer number (1029661907400).

Almost surely, 2^{81545090479520} is an apocalyptic number.

81545090479520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81545090479520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98847543110400).

81545090479520 is an abundant number, since it is smaller than the sum of its proper divisors (116149995741280).

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

81545090479520 is a wasteful number, since it uses less digits than its factorization.

81545090479520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55831 (or 55823 counting only the distinct ones).

The product of its (nonzero) digits is 18144000, while the sum is 59.

The spelling of 81545090479520 in words is "eighty-one trillion, five hundred forty-five billion, ninety million, four hundred seventy-nine thousand, five hundred twenty".