81189581310 has 160 divisors (see below), whose sum is σ = 220751451360. Its totient is φ = 21409339392.

The previous prime is 81189581299. The next prime is 81189581353. The reversal of 81189581310 is 1318598118.

81189581310 is a `hidden beast` number, since 81 + 189 + 5 + 81 + 310 = 666.

It is a super-2 number, since 2×81189581310² (a number of 23 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 56656354 + ... + 56657786.

It is an arithmetic number, because the mean of its divisors is an integer number (1379696571).

Almost surely, 2^81189581310 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81189581310, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110375725680).

81189581310 is an abundant number, since it is smaller than the sum of its proper divisors (139561870050).

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

81189581310 is a wasteful number, since it uses less digits than its factorization.

81189581310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2184 (or 2175 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 45.

The spelling of 81189581310 in words is "eighty-one billion, one hundred eighty-nine million, five hundred eighty-one thousand, three hundred ten".