21544455222 has 64 divisors (see below), whose sum is σ = 48740659200. Its totient is φ = 7052136480.

The previous prime is 21544455193. The next prime is 21544455223. The reversal of 21544455222 is 22255444512.

21544455222 is a `hidden beast` number, since 2 + 1 + 544 + 45 + 52 + 22 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21544455223) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 3460072 + ... + 3466292.

It is an arithmetic number, because the mean of its divisors is an integer number (761572800).

Almost surely, 2^21544455222 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21544455222, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24370329600).

21544455222 is an abundant number, since it is smaller than the sum of its proper divisors (27196203978).

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

21544455222 is a wasteful number, since it uses less digits than its factorization.

21544455222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7378 (or 7372 counting only the distinct ones).

The product of its digits is 128000, while the sum is 36.

Adding to 21544455222 its reverse (22255444512), we get a palindrome (43799899734).

The spelling of 21544455222 in words is "twenty-one billion, five hundred forty-four million, four hundred fifty-five thousand, two hundred twenty-two".