128436949 has 2 divisors, whose sum is σ = 128436950. Its totient is φ = 128436948.

The previous prime is 128436901. The next prime is 128437013. The reversal of 128436949 is 949634821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 117874449 + 10562500 = 10857^2 + 3250^2 .

It is an emirp because it is prime and its reverse (949634821) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128436949 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 128436899 and 128436908.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128430949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64218474 + 64218475.

It is an arithmetic number, because the mean of its divisors is an integer number (64218475).

Almost surely, 2^128436949 is an apocalyptic number.

It is an amenable number.

128436949 is a deficient number, since it is larger than the sum of its proper divisors (1).

128436949 is an equidigital number, since it uses as much as digits as its factorization.

128436949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 46.

The square root of 128436949 is about 11333.0026471364. The cubic root of 128436949 is about 504.5412282878.

The spelling of 128436949 in words is "one hundred twenty-eight million, four hundred thirty-six thousand, nine hundred forty-nine".