128780173 has 2 divisors, whose sum is σ = 128780174. Its totient is φ = 128780172.

The previous prime is 128780167. The next prime is 128780237. The reversal of 128780173 is 371087821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107371044 + 21409129 = 10362^2 + 4627^2 .

It is a cyclic number.

It is not a de Polignac number, because 128780173 - 2⁹ = 128779661 is a prime.

It is equal to p_7312897 and since 128780173 and 7312897 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 (128780143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64390086 + 64390087.

It is an arithmetic number, because the mean of its divisors is an integer number (64390087).

Almost surely, 2^128780173 is an apocalyptic number.

It is an amenable number.

128780173 is a deficient number, since it is larger than the sum of its proper divisors (1).

128780173 is an equidigital number, since it uses as much as digits as its factorization.

128780173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18816, while the sum is 37.

The square root of 128780173 is about 11348.1352212599. The cubic root of 128780173 is about 504.9902595906.

The spelling of 128780173 in words is "one hundred twenty-eight million, seven hundred eighty thousand, one hundred seventy-three".