55221144 has 128 divisors (see below), whose sum is σ = 161568000. Its totient is φ = 15552000.

The previous prime is 55221143. The next prime is 55221161. The reversal of 55221144 is 44112255.

55221144 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 (24).

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55221143) 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, 506562 + ... + 506670.

It is an arithmetic number, because the mean of its divisors is an integer number (1262250).

Almost surely, 2^55221144 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 55221144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80784000).

55221144 is an abundant number, since it is smaller than the sum of its proper divisors (106346856).

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

55221144 is a wasteful number, since it uses less digits than its factorization.

55221144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249 (or 245 counting only the distinct ones).

The product of its digits is 1600, while the sum is 24.

The square root of 55221144 is about 7431.0930555336. The cubic root of 55221144 is about 380.8042615099.

Adding to 55221144 its reverse (44112255), we get a palindrome (99333399).

Subtracting from 55221144 its reverse (44112255), we obtain a square (11108889 = 3333²).

It can be divided in two parts, 552211 and 44, that added together give a palindrome (552255).

The spelling of 55221144 in words is "fifty-five million, two hundred twenty-one thousand, one hundred forty-four".