81542248171 has 2 divisors, whose sum is σ = 81542248172. Its totient is φ = 81542248170.

The previous prime is 81542248163. The next prime is 81542248201. The reversal of 81542248171 is 17184224518.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81542248171 - 2³ = 81542248163 is a prime.

It is not a weakly prime, because it can be changed into another prime (81545248171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40771124085 + 40771124086.

It is an arithmetic number, because the mean of its divisors is an integer number (40771124086).

Almost surely, 2^81542248171 is an apocalyptic number.

81542248171 is a deficient number, since it is larger than the sum of its proper divisors (1).

81542248171 is an equidigital number, since it uses as much as digits as its factorization.

81542248171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 143360, while the sum is 43.

The spelling of 81542248171 in words is "eighty-one billion, five hundred forty-two million, two hundred forty-eight thousand, one hundred seventy-one".