128416221 has 12 divisors (see below), whose sum is σ = 185588572. Its totient is φ = 85565376.

The previous prime is 128416219. The next prime is 128416237. The reversal of 128416221 is 122614821.

128416221 is a `hidden beast` number, since 1 + 28 + 416 + 221 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 100220121 + 28196100 = 10011^2 + 5310^2 .

It is not a de Polignac number, because 128416221 - 2¹ = 128416219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128416201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29625 + ... + 33681.

Almost surely, 2^128416221 is an apocalyptic number.

It is an amenable number.

128416221 is a deficient number, since it is larger than the sum of its proper divisors (57172351).

128416221 is a wasteful number, since it uses less digits than its factorization.

128416221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7580 (or 7577 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 128416221 is about 11332.0881129649. The cubic root of 128416221 is about 504.5140847663.

The spelling of 128416221 in words is "one hundred twenty-eight million, four hundred sixteen thousand, two hundred twenty-one".