221328144 has 30 divisors (see below), whose sum is σ = 619411806. Its totient is φ = 73776000.

The previous prime is 221328119. The next prime is 221328161. The reversal of 221328144 is 441823122.

It can be written as a sum of positive squares in only one way, i.e., 195440400 + 25887744 = 13980^2 + 5088^2 .

It is a super-2 number, since 2×221328144² = 97972294652969472, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 768357 + ... + 768644.

Almost surely, 2^221328144 is an apocalyptic number.

221328144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

221328144 is an abundant number, since it is smaller than the sum of its proper divisors (398083662).

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

221328144 is a wasteful number, since it uses less digits than its factorization.

221328144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1537015 (or 1537006 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

The square root of 221328144 is about 14877.1013305684. The cubic root of 221328144 is about 604.8934484394.

It can be divided in two parts, 22132 and 8144, that added together give a square (30276 = 174²).

The spelling of 221328144 in words is "two hundred twenty-one million, three hundred twenty-eight thousand, one hundred forty-four".