128993911 has 2 divisors, whose sum is σ = 128993912. Its totient is φ = 128993910.

The previous prime is 128993899. The next prime is 128993923. The reversal of 128993911 is 119399821.

It is a balanced prime because it is at equal distance from previous prime (128993899) and next prime (128993923).

It is an emirp because it is prime and its reverse (119399821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128993911 - 2⁷ = 128993783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128993311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64496955 + 64496956.

It is an arithmetic number, because the mean of its divisors is an integer number (64496956).

Almost surely, 2^128993911 is an apocalyptic number.

128993911 is a deficient number, since it is larger than the sum of its proper divisors (1).

128993911 is an equidigital number, since it uses as much as digits as its factorization.

128993911 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 43.

The square root of 128993911 is about 11357.5486351589. The cubic root of 128993911 is about 505.2694846363.

The spelling of 128993911 in words is "one hundred twenty-eight million, nine hundred ninety-three thousand, nine hundred eleven".