221181515812 has 24 divisors (see below), whose sum is σ = 403945416000. Its totient is φ = 105769700256.

The previous prime is 221181515761. The next prime is 221181515813. The reversal of 221181515812 is 218515181122.

221181515812 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (221181515813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 644814 + ... + 926362.

It is an arithmetic number, because the mean of its divisors is an integer number (16831059000).

Almost surely, 2^221181515812 is an apocalyptic number.

It is an amenable number.

221181515812 is a deficient number, since it is larger than the sum of its proper divisors (182763900188).

221181515812 is a wasteful number, since it uses less digits than its factorization.

221181515812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290115 (or 290113 counting only the distinct ones).

The product of its digits is 12800, while the sum is 37.

Adding to 221181515812 its reverse (218515181122), we get a palindrome (439696696934).

The spelling of 221181515812 in words is "two hundred twenty-one billion, one hundred eighty-one million, five hundred fifteen thousand, eight hundred twelve".