81548400780 has 480 divisors, whose sum is σ = 329957591040. Its totient is φ = 16360081920.

The previous prime is 81548400761. The next prime is 81548400803. The reversal of 81548400780 is 8700484518.

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

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 159 ways as a sum of consecutive naturals, for example, 3606189 + ... + 3628731.

It is an arithmetic number, because the mean of its divisors is an integer number (687411648).

Almost surely, 2^81548400780 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 81548400780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164978795520).

81548400780 is an abundant number, since it is smaller than the sum of its proper divisors (248409190260).

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

81548400780 is a wasteful number, since it uses less digits than its factorization.

81548400780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22611 (or 22600 counting only the distinct ones).

The product of its (nonzero) digits is 286720, while the sum is 45.

The spelling of 81548400780 in words is "eighty-one billion, five hundred forty-eight million, four hundred thousand, seven hundred eighty".