81476808840 has 384 divisors, whose sum is σ = 315879782400. Its totient is φ = 17825034240.

The previous prime is 81476808811. The next prime is 81476808901. The reversal of 81476808840 is 4880867418.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5468521 + ... + 5483399.

It is an arithmetic number, because the mean of its divisors is an integer number (822603600).

Almost surely, 2^81476808840 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 81476808840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (157939891200).

81476808840 is an abundant number, since it is smaller than the sum of its proper divisors (234402973560).

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

81476808840 is a wasteful number, since it uses less digits than its factorization.

81476808840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14997 (or 14990 counting only the distinct ones).

The product of its (nonzero) digits is 2752512, while the sum is 54.

The spelling of 81476808840 in words is "eighty-one billion, four hundred seventy-six million, eight hundred eight thousand, eight hundred forty".