128739389 has 2 divisors, whose sum is σ = 128739390. Its totient is φ = 128739388.

The previous prime is 128739379. The next prime is 128739407. The reversal of 128739389 is 983937821.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 128436889 + 302500 = 11333^2 + 550^2 .

It is a cyclic number.

It is not a de Polignac number, because 128739389 - 2⁸ = 128739133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128739379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64369694 + 64369695.

It is an arithmetic number, because the mean of its divisors is an integer number (64369695).

Almost surely, 2^128739389 is an apocalyptic number.

It is an amenable number.

128739389 is a deficient number, since it is larger than the sum of its proper divisors (1).

128739389 is an equidigital number, since it uses as much as digits as its factorization.

128739389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 50.

The square root of 128739389 is about 11346.3381317498. The cubic root of 128739389 is about 504.9369447135.

The spelling of 128739389 in words is "one hundred twenty-eight million, seven hundred thirty-nine thousand, three hundred eighty-nine".