128366388021 has 8 divisors (see below), whose sum is σ = 171922696960. Its totient is φ = 85193835552.

The previous prime is 128366388019. The next prime is 128366388023. The reversal of 128366388021 is 120883663821.

It is an interprime number because it is at equal distance from previous prime (128366388019) and next prime (128366388023).

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

It is not a de Polignac number, because 128366388021 - 2¹ = 128366388019 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 (128366388023) 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, 95938336 + ... + 95939673.

It is an arithmetic number, because the mean of its divisors is an integer number (21490337120).

Almost surely, 2^128366388021 is an apocalyptic number.

It is an amenable number.

128366388021 is a deficient number, since it is larger than the sum of its proper divisors (43556308939).

128366388021 is a wasteful number, since it uses less digits than its factorization.

128366388021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191878235.

The product of its (nonzero) digits is 663552, while the sum is 48.

The spelling of 128366388021 in words is "one hundred twenty-eight billion, three hundred sixty-six million, three hundred eighty-eight thousand, twenty-one".