81271517793673 has 16 divisors (see below), whose sum is σ = 81854420528016. Its totient is φ = 80689990901760.

The previous prime is 81271517793611. The next prime is 81271517793679. The reversal of 81271517793673 is 37639771517218.

It can be written as a sum of positive squares in 8 ways, for example, as 7346550044304 + 73924967749369 = 2710452^2 + 8597963^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81271517793673 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81271517793599 and 81271517793608.

It is not an unprimeable number, because it can be changed into a prime (81271517793679) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 375035433 + ... + 375252073.

It is an arithmetic number, because the mean of its divisors is an integer number (5115901283001).

Almost surely, 2^{81271517793673} is an apocalyptic number.

It is an amenable number.

81271517793673 is a deficient number, since it is larger than the sum of its proper divisors (582902734343).

81271517793673 is a wasteful number, since it uses less digits than its factorization.

81271517793673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219804.

The product of its digits is 93350880, while the sum is 67.

The spelling of 81271517793673 in words is "eighty-one trillion, two hundred seventy-one billion, five hundred seventeen million, seven hundred ninety-three thousand, six hundred seventy-three".