128875421 has 2 divisors, whose sum is σ = 128875422. Its totient is φ = 128875420.

The previous prime is 128875393. The next prime is 128875447. The reversal of 128875421 is 124578821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128572921 + 302500 = 11339^2 + 550^2 .

It is a cyclic number.

It is not a de Polignac number, because 128875421 - 2²⁶ = 61766557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128875451) 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, 64437710 + 64437711.

It is an arithmetic number, because the mean of its divisors is an integer number (64437711).

Almost surely, 2^128875421 is an apocalyptic number.

It is an amenable number.

128875421 is a deficient number, since it is larger than the sum of its proper divisors (1).

128875421 is an equidigital number, since it uses as much as digits as its factorization.

128875421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35840, while the sum is 38.

The square root of 128875421 is about 11352.3310822051. The cubic root of 128875421 is about 505.1147286959.

The spelling of 128875421 in words is "one hundred twenty-eight million, eight hundred seventy-five thousand, four hundred twenty-one".