216305280 has 288 divisors, whose sum is σ = 808051140. Its totient is φ = 53133312.

The previous prime is 216305261. The next prime is 216305281. The reversal of 216305280 is 82503612.

216305280 is a `hidden beast` number, since 2 + 1 + 630 + 5 + 28 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 215032896 + 1272384 = 14664^2 + 1128^2 .

It is a tau number, because it is divible by the number of its divisors (288).

It is not an unprimeable number, because it can be changed into a prime (216305281) 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 35 ways as a sum of consecutive naturals, for example, 4602217 + ... + 4602263.

Almost surely, 2^216305280 is an apocalyptic number.

216305280 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 216305280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (404025570).

216305280 is an abundant number, since it is smaller than the sum of its proper divisors (591745860).

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

216305280 is a wasteful number, since it uses less digits than its factorization.

216305280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136 (or 74 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 216305280 is about 14707.3206261372. The cubic root of 216305280 is about 600.2825336037.

Adding to 216305280 its reverse (82503612), we get a palindrome (298808892).

The spelling of 216305280 in words is "two hundred sixteen million, three hundred five thousand, two hundred eighty".