81077538880 has 224 divisors, whose sum is σ = 219630394368. Its totient is φ = 28294963200.

The previous prime is 81077538869. The next prime is 81077538917. The reversal of 81077538880 is 8883577018.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5537970 + ... + 5552590.

It is an arithmetic number, because the mean of its divisors is an integer number (980492832).

Almost surely, 2^81077538880 is an apocalyptic number.

81077538880 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 81077538880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109815197184).

81077538880 is an abundant number, since it is smaller than the sum of its proper divisors (138552855488).

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

81077538880 is a wasteful number, since it uses less digits than its factorization.

81077538880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14725 (or 14715 counting only the distinct ones).

The product of its (nonzero) digits is 3010560, while the sum is 55.

The spelling of 81077538880 in words is "eighty-one billion, seventy-seven million, five hundred thirty-eight thousand, eight hundred eighty".