81147315208 has 16 divisors (see below), whose sum is σ = 152193382380. Its totient is φ = 40562413248.

The previous prime is 81147315191. The next prime is 81147315209. The reversal of 81147315208 is 80251374118.

It can be written as a sum of positive squares in 2 ways, for example, as 70893322564 + 10253992644 = 266258^2 + 101262^2 .

It is not an unprimeable number, because it can be changed into a prime (81147315209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1374835 + ... + 1432642.

Almost surely, 2^81147315208 is an apocalyptic number.

It is an amenable number.

81147315208 is a deficient number, since it is larger than the sum of its proper divisors (71046067172).

81147315208 is a wasteful number, since it uses less digits than its factorization.

81147315208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2811096 (or 2811092 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 40.

The spelling of 81147315208 in words is "eighty-one billion, one hundred forty-seven million, three hundred fifteen thousand, two hundred eight".