128399777 has 16 divisors (see below), whose sum is σ = 153861120. Its totient is φ = 105771600.

The previous prime is 128399717. The next prime is 128399779. The reversal of 128399777 is 777993821.

It is not a de Polignac number, because 128399777 - 2¹⁴ = 128383393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128399779) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8549 + ... + 18162.

It is an arithmetic number, because the mean of its divisors is an integer number (9616320).

Almost surely, 2^128399777 is an apocalyptic number.

It is an amenable number.

128399777 is a deficient number, since it is larger than the sum of its proper divisors (25461343).

128399777 is a wasteful number, since it uses less digits than its factorization.

128399777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26764.

The product of its digits is 1333584, while the sum is 53.

The square root of 128399777 is about 11331.3625394301. The cubic root of 128399777 is about 504.4925491076.

The spelling of 128399777 in words is "one hundred twenty-eight million, three hundred ninety-nine thousand, seven hundred seventy-seven".