55533220 has 48 divisors (see below), whose sum is σ = 124186608. Its totient is φ = 20787200.

The previous prime is 55533197. The next prime is 55533221. The reversal of 55533220 is 2233555.

It can be written as a sum of positive squares in 8 ways, for example, as 802816 + 54730404 = 896^2 + 7398^2 .

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (55533221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78870 + ... + 79570.

It is an arithmetic number, because the mean of its divisors is an integer number (2587221).

Almost surely, 2^55533220 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 55533220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62093304).

55533220 is an abundant number, since it is smaller than the sum of its proper divisors (68653388).

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

55533220 is a wasteful number, since it uses less digits than its factorization.

55533220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 960 (or 958 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 25.

The square root of 55533220 is about 7452.0614597573. The cubic root of 55533220 is about 381.5202716729.

Adding to 55533220 its reverse (2233555), we get a palindrome (57766775).

The spelling of 55533220 in words is "fifty-five million, five hundred thirty-three thousand, two hundred twenty".