81271521416 has 16 divisors (see below), whose sum is σ = 152412810000. Its totient is φ = 40628105424.

The previous prime is 81271521379. The next prime is 81271521421. The reversal of 81271521416 is 61412517218.

It is a self number, because there is not a number n which added to its sum of digits gives 81271521416.

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, 911666 + ... + 996833.

It is an arithmetic number, because the mean of its divisors is an integer number (9525800625).

Almost surely, 2^81271521416 is an apocalyptic number.

It is an amenable number.

81271521416 is a deficient number, since it is larger than the sum of its proper divisors (71141288584).

81271521416 is a wasteful number, since it uses less digits than its factorization.

81271521416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1913828 (or 1913824 counting only the distinct ones).

The product of its digits is 26880, while the sum is 38.

The spelling of 81271521416 in words is "eighty-one billion, two hundred seventy-one million, five hundred twenty-one thousand, four hundred sixteen".