128218321 has 8 divisors (see below), whose sum is σ = 159856704. Its totient is φ = 99910320.

The previous prime is 128218313. The next prime is 128218331. The reversal of 128218321 is 123812821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128218321 - 2³ = 128218313 is a prime.

It is a super-3 number, since 3×128218321³ (a number of 25 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 128218321.

It is not an unprimeable number, because it can be changed into a prime (128218331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 832510 + ... + 832663.

It is an arithmetic number, because the mean of its divisors is an integer number (19982088).

Almost surely, 2^128218321 is an apocalyptic number.

128218321 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

128218321 is a deficient number, since it is larger than the sum of its proper divisors (31638383).

128218321 is a wasteful number, since it uses less digits than its factorization.

128218321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1665191.

The product of its digits is 1536, while the sum is 28.

The square root of 128218321 is about 11323.3529045067. The cubic root of 128218321 is about 504.2547855659.

The spelling of 128218321 in words is "one hundred twenty-eight million, two hundred eighteen thousand, three hundred twenty-one".