81098870780 has 96 divisors (see below), whose sum is σ = 187335590400. Its totient is φ = 29353598208.

The previous prime is 81098870771. The next prime is 81098870819. The reversal of 81098870780 is 8707889018.

It is a super-2 number, since 2×81098870780² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6400091 + ... + 6412749.

It is an arithmetic number, because the mean of its divisors is an integer number (1951412400).

Almost surely, 2^81098870780 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 81098870780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93667795200).

81098870780 is an abundant number, since it is smaller than the sum of its proper divisors (106236719620).

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

81098870780 is a wasteful number, since it uses less digits than its factorization.

81098870780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13443 (or 13441 counting only the distinct ones).

The product of its (nonzero) digits is 1806336, while the sum is 56.

The spelling of 81098870780 in words is "eighty-one billion, ninety-eight million, eight hundred seventy thousand, seven hundred eighty".