128445647 has 4 divisors (see below), whose sum is σ = 140122536. Its totient is φ = 116768760.

The previous prime is 128445623. The next prime is 128445671. The reversal of 128445647 is 746544821.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (128445623) and next prime (128445671).

It is a cyclic number.

It is not a de Polignac number, because 128445647 - 2²⁶ = 61336783 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 (128445347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5838428 + ... + 5838449.

It is an arithmetic number, because the mean of its divisors is an integer number (35030634).

Almost surely, 2^128445647 is an apocalyptic number.

128445647 is a deficient number, since it is larger than the sum of its proper divisors (11676889).

128445647 is a wasteful number, since it uses less digits than its factorization.

128445647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11676888.

The product of its digits is 215040, while the sum is 41.

The square root of 128445647 is about 11333.3863871307. The cubic root of 128445647 is about 504.5526175351.

The spelling of 128445647 in words is "one hundred twenty-eight million, four hundred forty-five thousand, six hundred forty-seven".