81105530880 has 416 divisors, whose sum is σ = 290101367808. Its totient is φ = 19175833600.

The previous prime is 81105530873. The next prime is 81105530923. The reversal of 81105530880 is 8803550118.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27707977 + ... + 27710903.

Almost surely, 2^81105530880 is an apocalyptic number.

81105530880 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 81105530880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145050683904).

81105530880 is an abundant number, since it is smaller than the sum of its proper divisors (208995836928).

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

81105530880 is a wasteful number, since it uses less digits than its factorization.

81105530880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3011 (or 2989 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 39.

The spelling of 81105530880 in words is "eighty-one billion, one hundred five million, five hundred thirty thousand, eight hundred eighty".