221428013328 has 120 divisors (see below), whose sum is σ = 631014279168. Its totient is φ = 72472651776.

The previous prime is 221428013299. The next prime is 221428013351. The reversal of 221428013328 is 823310824122.

221428013328 is a `hidden beast` number, since 221 + 4 + 280 + 133 + 28 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 221428013292 and 221428013301.

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, 1711525 + ... + 1836347.

Almost surely, 2^221428013328 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 221428013328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (315507139584).

221428013328 is an abundant number, since it is smaller than the sum of its proper divisors (409586265840).

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

221428013328 is a wasteful number, since it uses less digits than its factorization.

221428013328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125061 (or 125052 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The spelling of 221428013328 in words is "two hundred twenty-one billion, four hundred twenty-eight million, thirteen thousand, three hundred twenty-eight".