55222728 has 64 divisors (see below), whose sum is σ = 155822400. Its totient is φ = 16154880.

The previous prime is 55222723. The next prime is 55222733. The reversal of 55222728 is 82722255.

It is an interprime number because it is at equal distance from previous prime (55222723) and next prime (55222733).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (55222723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4050 + ... + 11262.

It is an arithmetic number, because the mean of its divisors is an integer number (2434725).

Almost surely, 2^55222728 is an apocalyptic number.

55222728 is a gapful number since it is divisible by the number (58) 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 55222728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77911200).

55222728 is an abundant number, since it is smaller than the sum of its proper divisors (100599672).

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

55222728 is a wasteful number, since it uses less digits than its factorization.

55222728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7262 (or 7258 counting only the distinct ones).

The product of its digits is 22400, while the sum is 33.

The square root of 55222728 is about 7431.1996339757. The cubic root of 55222728 is about 380.8079025559.

It can be divided in two parts, 552227 and 28, that added together give a palindrome (552255).

The spelling of 55222728 in words is "fifty-five million, two hundred twenty-two thousand, seven hundred twenty-eight".