81273538196 has 6 divisors (see below), whose sum is σ = 142228691850. Its totient is φ = 40636769096.

The previous prime is 81273538189. The next prime is 81273538249. The reversal of 81273538196 is 69183537218.

It can be written as a sum of positive squares in only one way, i.e., 56375854096 + 24897684100 = 237436^2 + 157790^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10159192271 + ... + 10159192278.

It is an arithmetic number, because the mean of its divisors is an integer number (23704781975).

Almost surely, 2^81273538196 is an apocalyptic number.

It is an amenable number.

81273538196 is a deficient number, since it is larger than the sum of its proper divisors (60955153654).

81273538196 is a wasteful number, since it uses less digits than its factorization.

81273538196 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20318384553 (or 20318384551 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 53.

The spelling of 81273538196 in words is "eighty-one billion, two hundred seventy-three million, five hundred thirty-eight thousand, one hundred ninety-six".