81542248168 has 32 divisors (see below), whose sum is σ = 160953271200.
Its totient is φ = 38621765952.
The previous prime is 81542248163. The next prime is 81542248171. The reversal of 81542248168 is 86184224518.
It is not an unprimeable number, because it can be changed into a prime (81542248163) by changing a digit.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2535646 + ... + 2567602.
It is an arithmetic number, because the mean of its divisors is an integer number (5029789725).
Almost surely, 281542248168 is an apocalyptic number.
It is an amenable number.
81542248168 is a deficient number, since it is larger than the sum of its proper divisors (79411023032).
81542248168 is a wasteful number, since it uses less digits than its factorization.
81542248168 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 48769 (or 48765 counting only the distinct ones).
The product of its digits is 983040, while the sum is 49.
The spelling of 81542248168 in words is "eighty-one billion, five hundred forty-two million, two hundred forty-eight thousand, one hundred sixty-eight".