128365639 has 2 divisors, whose sum is σ = 128365640. Its totient is φ = 128365638.

The previous prime is 128365619. The next prime is 128365661. The reversal of 128365639 is 936563821.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128365639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 128365595 and 128365604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128365619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64182819 + 64182820.

It is an arithmetic number, because the mean of its divisors is an integer number (64182820).

Almost surely, 2^128365639 is an apocalyptic number.

128365639 is a deficient number, since it is larger than the sum of its proper divisors (1).

128365639 is an equidigital number, since it uses as much as digits as its factorization.

128365639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 233280, while the sum is 43.

The square root of 128365639 is about 11329.8560891125. The cubic root of 128365639 is about 504.4478348731.

The spelling of 128365639 in words is "one hundred twenty-eight million, three hundred sixty-five thousand, six hundred thirty-nine".