81342671816 has 64 divisors (see below), whose sum is σ = 184830698880. Its totient is φ = 32762188800.

The previous prime is 81342671797. The next prime is 81342671819. The reversal of 81342671816 is 61817624318.

It is not an unprimeable number, because it can be changed into a prime (81342671819) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 587666 + ... + 712766.

It is an arithmetic number, because the mean of its divisors is an integer number (2887979670).

Almost surely, 2^81342671816 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 81342671816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92415349440).

81342671816 is an abundant number, since it is smaller than the sum of its proper divisors (103488027064).

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

81342671816 is a wasteful number, since it uses less digits than its factorization.

81342671816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125814 (or 125810 counting only the distinct ones).

The product of its digits is 387072, while the sum is 47.

The spelling of 81342671816 in words is "eighty-one billion, three hundred forty-two million, six hundred seventy-one thousand, eight hundred sixteen".