128030021 has 8 divisors (see below), whose sum is σ = 149433600. Its totient is φ = 107404848.

The previous prime is 128029991. The next prime is 128030051. The reversal of 128030021 is 120030821.

It is an interprime number because it is at equal distance from previous prime (128029991) and next prime (128030051).

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 128030021 - 2²² = 123835717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128030051) 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 7 ways as a sum of consecutive naturals, for example, 194246 + ... + 194903.

It is an arithmetic number, because the mean of its divisors is an integer number (18679200).

Almost surely, 2^128030021 is an apocalyptic number.

It is an amenable number.

128030021 is a deficient number, since it is larger than the sum of its proper divisors (21403579).

128030021 is an equidigital number, since it uses as much as digits as its factorization.

128030021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389203.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 128030021 is about 11315.0351744924. The cubic root of 128030021 is about 504.0078169716.

Adding to 128030021 its reverse (120030821), we get a palindrome (248060842).

The spelling of 128030021 in words is "one hundred twenty-eight million, thirty thousand, twenty-one".