128430821 has 8 divisors (see below), whose sum is σ = 132991200. Its totient is φ = 123879280.

The previous prime is 128430791. The next prime is 128430833. The reversal of 128430821 is 128034821.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128430821 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128430851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44150 + ... + 46968.

It is an arithmetic number, because the mean of its divisors is an integer number (16623900).

Almost surely, 2^128430821 is an apocalyptic number.

It is an amenable number.

128430821 is a deficient number, since it is larger than the sum of its proper divisors (4560379).

128430821 is a wasteful number, since it uses less digits than its factorization.

128430821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4419.

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 128430821 is about 11332.7322830816. The cubic root of 128430821 is about 504.5332039151.

The spelling of 128430821 in words is "one hundred twenty-eight million, four hundred thirty thousand, eight hundred twenty-one".