81090380580 has 144 divisors (see below), whose sum is σ = 256531713984. Its totient is φ = 18980272640.

The previous prime is 81090380549. The next prime is 81090380597. The reversal of 81090380580 is 8508309018.

It is a super-3 number, since 3×81090380580³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 482014 + ... + 628106.

It is an arithmetic number, because the mean of its divisors is an integer number (1781470236).

Almost surely, 2^81090380580 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 81090380580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128265856992).

81090380580 is an abundant number, since it is smaller than the sum of its proper divisors (175441333404).

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

81090380580 is a wasteful number, since it uses less digits than its factorization.

81090380580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146174 (or 146143 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 42.

Adding to 81090380580 its reverse (8508309018), we get a palindrome (89598689598).

The spelling of 81090380580 in words is "eighty-one billion, ninety million, three hundred eighty thousand, five hundred eighty".