128403857 has 2 divisors, whose sum is σ = 128403858. Its totient is φ = 128403856.

The previous prime is 128403827. The next prime is 128403901. The reversal of 128403857 is 758304821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 102434641 + 25969216 = 10121^2 + 5096^2 .

It is an emirp because it is prime and its reverse (758304821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128403857 - 2²⁰ = 127355281 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 128403857.

It is not a weakly prime, because it can be changed into another prime (128403827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64201928 + 64201929.

It is an arithmetic number, because the mean of its divisors is an integer number (64201929).

Almost surely, 2^128403857 is an apocalyptic number.

It is an amenable number.

128403857 is a deficient number, since it is larger than the sum of its proper divisors (1).

128403857 is an equidigital number, since it uses as much as digits as its factorization.

128403857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 53760, while the sum is 38.

The square root of 128403857 is about 11331.5425693063. The cubic root of 128403857 is about 504.4978925950.

The spelling of 128403857 in words is "one hundred twenty-eight million, four hundred three thousand, eight hundred fifty-seven".