81272932804871 has 4 divisors (see below), whose sum is σ = 83469498556392. Its totient is φ = 79076367053352.

The previous prime is 81272932804867. The next prime is 81272932804883. The reversal of 81272932804871 is 17840823927218.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81272932804871 - 2² = 81272932804867 is a prime.

It is a super-2 number, since 2×81272932804871² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81272932804891) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1098282875705 + ... + 1098282875778.

It is an arithmetic number, because the mean of its divisors is an integer number (20867374639098).

Almost surely, 2^{81272932804871} is an apocalyptic number.

81272932804871 is a deficient number, since it is larger than the sum of its proper divisors (2196565751521).

81272932804871 is a wasteful number, since it uses less digits than its factorization.

81272932804871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2196565751520.

The product of its (nonzero) digits is 21676032, while the sum is 62.

The spelling of 81272932804871 in words is "eighty-one trillion, two hundred seventy-two billion, nine hundred thirty-two million, eight hundred four thousand, eight hundred seventy-one".