81168442238 has 16 divisors (see below), whose sum is σ = 136819047456. Its totient is φ = 35833559520.

The previous prime is 81168442211. The next prime is 81168442259. The reversal of 81168442238 is 83224486118.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81168442192 and 81168442201.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67865993 + ... + 67867188.

It is an arithmetic number, because the mean of its divisors is an integer number (8551190466).

Almost surely, 2^81168442238 is an apocalyptic number.

81168442238 is a deficient number, since it is larger than the sum of its proper divisors (55650605218).

81168442238 is a wasteful number, since it uses less digits than its factorization.

81168442238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135733219.

The product of its digits is 589824, while the sum is 47.

The spelling of 81168442238 in words is "eighty-one billion, one hundred sixty-eight million, four hundred forty-two thousand, two hundred thirty-eight".