128444647 has 4 divisors (see below), whose sum is σ = 128467360. Its totient is φ = 128421936.

The previous prime is 128444633. The next prime is 128444651. The reversal of 128444647 is 746444821.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 746444821 = 199 ⋅3750979.

It is a cyclic number.

It is not a de Polignac number, because 128444647 - 2²³ = 120056039 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 (128444347) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4603 + ... + 16675.

It is an arithmetic number, because the mean of its divisors is an integer number (32116840).

Almost surely, 2^128444647 is an apocalyptic number.

128444647 is a deficient number, since it is larger than the sum of its proper divisors (22713).

128444647 is a wasteful number, since it uses less digits than its factorization.

128444647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22712.

The product of its digits is 172032, while the sum is 40.

The square root of 128444647 is about 11333.3422696043. The cubic root of 128444647 is about 504.5513081514.

The spelling of 128444647 in words is "one hundred twenty-eight million, four hundred forty-four thousand, six hundred forty-seven".