128638837 has 2 divisors, whose sum is σ = 128638838. Its totient is φ = 128638836.

The previous prime is 128638831. The next prime is 128638849. The reversal of 128638837 is 738836821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71470116 + 57168721 = 8454^2 + 7561^2 .

It is an emirp because it is prime and its reverse (738836821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128638837 - 2¹¹ = 128636789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128638831) 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 as a sum of consecutive naturals, namely, 64319418 + 64319419.

It is an arithmetic number, because the mean of its divisors is an integer number (64319419).

Almost surely, 2^128638837 is an apocalyptic number.

It is an amenable number.

128638837 is a deficient number, since it is larger than the sum of its proper divisors (1).

128638837 is an equidigital number, since it uses as much as digits as its factorization.

128638837 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 387072, while the sum is 46.

The square root of 128638837 is about 11341.9062330809. The cubic root of 128638837 is about 504.8054500083.

The spelling of 128638837 in words is "one hundred twenty-eight million, six hundred thirty-eight thousand, eight hundred thirty-seven".