221218800 has 120 divisors (see below), whose sum is σ = 773105280. Its totient is φ = 53625600.

The previous prime is 221218799. The next prime is 221218817. The reversal of 221218800 is 8812122.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4821 + ... + 21579.

It is an arithmetic number, because the mean of its divisors is an integer number (6442544).

Almost surely, 2^221218800 is an apocalyptic number.

221218800 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 221218800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (386552640).

221218800 is an abundant number, since it is smaller than the sum of its proper divisors (551886480).

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

221218800 is a wasteful number, since it uses less digits than its factorization.

221218800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16791 (or 16780 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 221218800 is about 14873.4259671402. The cubic root of 221218800 is about 604.7938190488.

It can be divided in two parts, 2212 and 18800, that added together give a palindrome (21012).

The spelling of 221218800 in words is "two hundred twenty-one million, two hundred eighteen thousand, eight hundred".