216621200 has 60 divisors (see below), whose sum is σ = 523264500. Its totient is φ = 86177280.

The previous prime is 216621193. The next prime is 216621217. The reversal of 216621200 is 2126612.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 295936 + 216325264 = 544^2 + 14708^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

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 11 ways as a sum of consecutive naturals, for example, 77426 + ... + 80174.

It is an arithmetic number, because the mean of its divisors is an integer number (8721075).

Almost surely, 2^216621200 is an apocalyptic number.

216621200 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 216621200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261632250).

216621200 is an abundant number, since it is smaller than the sum of its proper divisors (306643300).

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

216621200 is a wasteful number, since it uses less digits than its factorization.

216621200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2964 (or 2953 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 216621200 is about 14718.0569369737. The cubic root of 216621200 is about 600.5746346678.

Adding to 216621200 its reverse (2126612), we get a palindrome (218747812).

The spelling of 216621200 in words is "two hundred sixteen million, six hundred twenty-one thousand, two hundred".