81673073516 has 6 divisors (see below), whose sum is σ = 142927878660. Its totient is φ = 40836536756.

The previous prime is 81673073507. The next prime is 81673073519. The reversal of 81673073516 is 61537037618.

It is not an unprimeable number, because it can be changed into a prime (81673073519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10209134186 + ... + 10209134193.

It is an arithmetic number, because the mean of its divisors is an integer number (23821313110).

Almost surely, 2^81673073516 is an apocalyptic number.

It is an amenable number.

81673073516 is a deficient number, since it is larger than the sum of its proper divisors (61254805144).

81673073516 is a wasteful number, since it uses less digits than its factorization.

81673073516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20418268383 (or 20418268381 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 47.

The spelling of 81673073516 in words is "eighty-one billion, six hundred seventy-three million, seventy-three thousand, five hundred sixteen".