81171827063 has 2 divisors, whose sum is σ = 81171827064. Its totient is φ = 81171827062.

The previous prime is 81171827039. The next prime is 81171827111. The reversal of 81171827063 is 36072817118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81171827063 - 2¹⁸ = 81171564919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81171827663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40585913531 + 40585913532.

It is an arithmetic number, because the mean of its divisors is an integer number (40585913532).

Almost surely, 2^81171827063 is an apocalyptic number.

81171827063 is a deficient number, since it is larger than the sum of its proper divisors (1).

81171827063 is an equidigital number, since it uses as much as digits as its factorization.

81171827063 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112896, while the sum is 44.

The spelling of 81171827063 in words is "eighty-one billion, one hundred seventy-one million, eight hundred twenty-seven thousand, sixty-three".