12205543644 has 120 divisors (see below), whose sum is σ = 36965980128. Its totient is φ = 3439480320.

The previous prime is 12205543621. The next prime is 12205543663. The reversal of 12205543644 is 44634550221.

12205543644 is a `hidden beast` number, since 1 + 2 + 2 + 0 + 5 + 5 + 4 + 3 + 644 = 666.

12205543644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 12205543599 and 12205543608.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 128704 + ... + 202424.

Almost surely, 2^12205543644 is an apocalyptic number.

12205543644 is a gapful number since it is divisible by the number (14) 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 12205543644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18482990064).

12205543644 is an abundant number, since it is smaller than the sum of its proper divisors (24760436484).

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

12205543644 is a wasteful number, since it uses less digits than its factorization.

12205543644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73817 (or 73806 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 36.

The spelling of 12205543644 in words is "twelve billion, two hundred five million, five hundred forty-three thousand, six hundred forty-four".