81665847722 has 8 divisors (see below), whose sum is σ = 122501801856. Its totient is φ = 40831913772.

The previous prime is 81665847707. The next prime is 81665847751. The reversal of 81665847722 is 22774856618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 399578 + ... + 568325.

It is an arithmetic number, because the mean of its divisors is an integer number (15312725232).

Almost surely, 2^81665847722 is an apocalyptic number.

81665847722 is a deficient number, since it is larger than the sum of its proper divisors (40835954134).

81665847722 is a wasteful number, since it uses less digits than its factorization.

81665847722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010092.

The product of its digits is 9031680, while the sum is 56.

The spelling of 81665847722 in words is "eighty-one billion, six hundred sixty-five million, eight hundred forty-seven thousand, seven hundred twenty-two".