12155220544 has 112 divisors (see below), whose sum is σ = 25485425280. Its totient is φ = 5744148480.

The previous prime is 12155220491. The next prime is 12155220551. The reversal of 12155220544 is 44502255121.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19263109 + ... + 19263739.

It is an arithmetic number, because the mean of its divisors is an integer number (227548440).

Almost surely, 2^12155220544 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12155220544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12742712640).

12155220544 is an abundant number, since it is smaller than the sum of its proper divisors (13330204736).

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

12155220544 is a wasteful number, since it uses less digits than its factorization.

12155220544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 876 (or 866 counting only the distinct ones).

The product of its (nonzero) digits is 16000, while the sum is 31.

Adding to 12155220544 its reverse (44502255121), we get a palindrome (56657475665).

The spelling of 12155220544 in words is "twelve billion, one hundred fifty-five million, two hundred twenty thousand, five hundred forty-four".