218581428 has 48 divisors (see below), whose sum is σ = 550854080. Its totient is φ = 67060224.

The previous prime is 218581421. The next prime is 218581469. The reversal of 218581428 is 824185812.

It is a Harshad number since it is a multiple of its sum of digits (39).

218581428 is a Rhonda number in base 10.

Its product of digits (40960) is a multiple of the sum of its prime factors (4096).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218581421) 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 15 ways as a sum of consecutive naturals, for example, 57276 + ... + 60972.

Almost surely, 2^218581428 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 218581428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (275427040).

218581428 is an abundant number, since it is smaller than the sum of its proper divisors (332272652).

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

218581428 is a wasteful number, since it uses less digits than its factorization.

218581428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4096 (or 4094 counting only the distinct ones).

The product of its digits is 40960, while the sum is 39.

The square root of 218581428 is about 14784.4995857148. The cubic root of 218581428 is about 602.3807519833.

The spelling of 218581428 in words is "two hundred eighteen million, five hundred eighty-one thousand, four hundred twenty-eight".