128972643 has 8 divisors (see below), whose sum is σ = 174878400. Its totient is φ = 84524328.

The previous prime is 128972629. The next prime is 128972647. The reversal of 128972643 is 346279821.

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

It is not a de Polignac number, because 128972643 - 2⁵ = 128972611 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 128972595 and 128972604.

It is not an unprimeable number, because it can be changed into a prime (128972647) 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, 364153 + ... + 364506.

It is an arithmetic number, because the mean of its divisors is an integer number (21859800).

Almost surely, 2^128972643 is an apocalyptic number.

128972643 is a deficient number, since it is larger than the sum of its proper divisors (45905757).

128972643 is an equidigital number, since it uses as much as digits as its factorization.

128972643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 728721.

The product of its digits is 145152, while the sum is 42.

The square root of 128972643 is about 11356.6123029713. The cubic root of 128972643 is about 505.2417141730.

The spelling of 128972643 in words is "one hundred twenty-eight million, nine hundred seventy-two thousand, six hundred forty-three".