81224642218 has 16 divisors (see below), whose sum is σ = 122043841920. Its totient is φ = 40543405056.

The previous prime is 81224642197. The next prime is 81224642263.

81224642218 is nontrivially palindromic in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4492705 + ... + 4510747.

It is an arithmetic number, because the mean of its divisors is an integer number (7627740120).

Almost surely, 2^81224642218 is an apocalyptic number.

81224642218 is a deficient number, since it is larger than the sum of its proper divisors (40819199702).

81224642218 is a wasteful number, since it uses less digits than its factorization.

81224642218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21741.

The product of its digits is 98304, while the sum is 40.

The spelling of 81224642218 in words is "eighty-one billion, two hundred twenty-four million, six hundred forty-two thousand, two hundred eighteen".