81471716721211 has 8 divisors (see below), whose sum is σ = 83137217133024. Its totient is φ = 79810968095040.

The previous prime is 81471716721203. The next prime is 81471716721233. The reversal of 81471716721211 is 11212761717418.

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

It is a cyclic number.

It is not a de Polignac number, because 81471716721211 - 2³ = 81471716721203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81471716721911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1187911770 + ... + 1187980351.

It is an arithmetic number, because the mean of its divisors is an integer number (10392152141628).

Almost surely, 2^{81471716721211} is an apocalyptic number.

81471716721211 is a deficient number, since it is larger than the sum of its proper divisors (1665500411813).

81471716721211 is a wasteful number, since it uses less digits than its factorization.

81471716721211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2375892821.

The product of its digits is 263424, while the sum is 49.

The spelling of 81471716721211 in words is "eighty-one trillion, four hundred seventy-one billion, seven hundred sixteen million, seven hundred twenty-one thousand, two hundred eleven".