81212421218 has 16 divisors (see below), whose sum is σ = 122237564064. Its totient is φ = 40466615040.

The previous prime is 81212421139. The next prime is 81212421229.

81212421218 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, 5297921 + ... + 5313227.

It is an arithmetic number, because the mean of its divisors is an integer number (7639847754).

Almost surely, 2^81212421218 is an apocalyptic number.

81212421218 is a deficient number, since it is larger than the sum of its proper divisors (41025142846).

81212421218 is a wasteful number, since it uses less digits than its factorization.

81212421218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24257.

The product of its digits is 4096, while the sum is 32.

The spelling of 81212421218 in words is "eighty-one billion, two hundred twelve million, four hundred twenty-one thousand, two hundred eighteen".