221144400 has 180 divisors, whose sum is σ = 784360512. Its totient is φ = 57672960.

The previous prime is 221144393. The next prime is 221144411. The reversal of 221144400 is 4441122.

221144400 is a `hidden beast` number, since 221 + 1 + 4 + 440 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a zygodrome in base 10.

It is a congruent number.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 168547 + ... + 169853.

Almost surely, 2^221144400 is an apocalyptic number.

221144400 is a gapful number since it is divisible by the number (20) 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 221144400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (392180256).

221144400 is an abundant number, since it is smaller than the sum of its proper divisors (563216112).

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

221144400 is a wasteful number, since it uses less digits than its factorization.

221144400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1378 (or 1364 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 221144400 is about 14870.9246518164. The cubic root of 221144400 is about 604.7260103070.

Adding to 221144400 its reverse (4441122), we get a palindrome (225585522).

The spelling of 221144400 in words is "two hundred twenty-one million, one hundred forty-four thousand, four hundred".