81663555167 has 2 divisors, whose sum is σ = 81663555168. Its totient is φ = 81663555166.

The previous prime is 81663555157. The next prime is 81663555179. The reversal of 81663555167 is 76155536618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81663555167 - 2¹⁴ = 81663538783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81663555157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40831777583 + 40831777584.

It is an arithmetic number, because the mean of its divisors is an integer number (40831777584).

Almost surely, 2^81663555167 is an apocalyptic number.

81663555167 is a deficient number, since it is larger than the sum of its proper divisors (1).

81663555167 is an equidigital number, since it uses as much as digits as its factorization.

81663555167 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536000, while the sum is 53.

The spelling of 81663555167 in words is "eighty-one billion, six hundred sixty-three million, five hundred fifty-five thousand, one hundred sixty-seven".