128923199 has 4 divisors (see below), whose sum is σ = 128989320. Its totient is φ = 128857080.

The previous prime is 128923187. The next prime is 128923217. The reversal of 128923199 is 991329821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 991329821 = 109 ⋅9094769.

It is a cyclic number.

It is not a de Polignac number, because 128923199 - 2¹² = 128919103 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 (128920199) 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 in 3 ways as a sum of consecutive naturals, for example, 30044 + ... + 34065.

It is an arithmetic number, because the mean of its divisors is an integer number (32247330).

Almost surely, 2^128923199 is an apocalyptic number.

128923199 is a deficient number, since it is larger than the sum of its proper divisors (66121).

128923199 is an equidigital number, since it uses as much as digits as its factorization.

128923199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66120.

The product of its digits is 69984, while the sum is 44.

The square root of 128923199 is about 11354.4352127263. The cubic root of 128923199 is about 505.1771413981.

It can be divided in two parts, 1289 and 23199, that multiplied together give a triangular number (29903511 = T₇₇₃₃).

The spelling of 128923199 in words is "one hundred twenty-eight million, nine hundred twenty-three thousand, one hundred ninety-nine".