12215221500 has 96 divisors (see below), whose sum is σ = 35600737536. Its totient is φ = 3254644800.

The previous prime is 12215221489. The next prime is 12215221507. The reversal of 12215221500 is 512251221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12215221507) 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 31 ways as a sum of consecutive naturals, for example, 2281827 + ... + 2287173.

It is an arithmetic number, because the mean of its divisors is an integer number (370841016).

Almost surely, 2^12215221500 is an apocalyptic number.

12215221500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12215221500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17800368768).

12215221500 is an abundant number, since it is smaller than the sum of its proper divisors (23385516036).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12215221500 is a wasteful number, since it uses less digits than its factorization.

12215221500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6892 (or 6880 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 21.

Adding to 12215221500 its reverse (512251221), we get a palindrome (12727472721).

The spelling of 12215221500 in words is "twelve billion, two hundred fifteen million, two hundred twenty-one thousand, five hundred".