218821064 has 96 divisors (see below), whose sum is σ = 537788160. Its totient is φ = 82454400.

The previous prime is 218821063. The next prime is 218821087. The reversal of 218821064 is 460128812.

218821064 = T₁₇ + T₁₈ + ... + T₁₀₉₄.

It is a happy number.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 218821064.

It is not an unprimeable number, because it can be changed into a prime (218821063) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 132854 + ... + 134490.

It is an arithmetic number, because the mean of its divisors is an integer number (5601960).

Almost surely, 2^218821064 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218821064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (268894080).

218821064 is an abundant number, since it is smaller than the sum of its proper divisors (318967096).

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

218821064 is a wasteful number, since it uses less digits than its factorization.

218821064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1699 (or 1688 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 218821064 is about 14792.6016643456. The cubic root of 218821064 is about 602.6008063510.

Adding to 218821064 its reverse (460128812), we get a palindrome (678949876).

The spelling of 218821064 in words is "two hundred eighteen million, eight hundred twenty-one thousand, sixty-four".