81659163 has 16 divisors (see below), whose sum is σ = 111582720. Its totient is φ = 53095776.

The previous prime is 81659161. The next prime is 81659173. The reversal of 81659163 is 36195618.

It is not a de Polignac number, because 81659163 - 2¹ = 81659161 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81659161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48093 + ... + 49761.

It is an arithmetic number, because the mean of its divisors is an integer number (6973920).

Almost surely, 2^81659163 is an apocalyptic number.

81659163 is a deficient number, since it is larger than the sum of its proper divisors (29923557).

81659163 is a wasteful number, since it uses less digits than its factorization.

81659163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2066.

The product of its digits is 38880, while the sum is 39.

The square root of 81659163 is about 9036.5459662417. The cubic root of 81659163 is about 433.8453776809.

The spelling of 81659163 in words is "eighty-one million, six hundred fifty-nine thousand, one hundred sixty-three".