128821559 has 4 divisors (see below), whose sum is σ = 129211080. Its totient is φ = 128432040.

The previous prime is 128821547. The next prime is 128821607. The reversal of 128821559 is 955128821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128821559 - 2⁴ = 128821543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128821519) 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 in 3 ways as a sum of consecutive naturals, for example, 194264 + ... + 194925.

It is an arithmetic number, because the mean of its divisors is an integer number (32302770).

Almost surely, 2^128821559 is an apocalyptic number.

128821559 is a deficient number, since it is larger than the sum of its proper divisors (389521).

128821559 is an equidigital number, since it uses as much as digits as its factorization.

128821559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389520.

The product of its digits is 57600, while the sum is 41.

The square root of 128821559 is about 11349.9585461798. The cubic root of 128821559 is about 505.0443499265.

It can be divided in two parts, 12882 and 1559, that added together give a palindrome (14441).

The spelling of 128821559 in words is "one hundred twenty-eight million, eight hundred twenty-one thousand, five hundred fifty-nine".