128725823 has 2 divisors, whose sum is σ = 128725824. Its totient is φ = 128725822.

The previous prime is 128725811. The next prime is 128725829. The reversal of 128725823 is 328527821.

It is a strong prime.

It is an emirp because it is prime and its reverse (328527821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128725823 - 2²⁰ = 127677247 is a prime.

It is equal to p_7309928 and since 128725823 and 7309928 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128725829) 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, 64362911 + 64362912.

It is an arithmetic number, because the mean of its divisors is an integer number (64362912).

Almost surely, 2^128725823 is an apocalyptic number.

128725823 is a deficient number, since it is larger than the sum of its proper divisors (1).

128725823 is an equidigital number, since it uses as much as digits as its factorization.

128725823 is an odious number, because the sum of its binary digits is odd.

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

The square root of 128725823 is about 11345.7403019812. The cubic root of 128725823 is about 504.9192080667.

The spelling of 128725823 in words is "one hundred twenty-eight million, seven hundred twenty-five thousand, eight hundred twenty-three".