128761111 has 4 divisors (see below), whose sum is σ = 136335312. Its totient is φ = 121186912.

The previous prime is 128761103. The next prime is 128761117. The reversal of 128761111 is 111167821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128761111 - 2³ = 128761103 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128761111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128761117) 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 in 3 ways as a sum of consecutive naturals, for example, 3787075 + ... + 3787108.

It is an arithmetic number, because the mean of its divisors is an integer number (34083828).

Almost surely, 2^128761111 is an apocalyptic number.

128761111 is a deficient number, since it is larger than the sum of its proper divisors (7574201).

128761111 is an equidigital number, since it uses as much as digits as its factorization.

128761111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7574200.

The product of its digits is 672, while the sum is 28.

The square root of 128761111 is about 11347.2953165060. The cubic root of 128761111 is about 504.9653421956.

The spelling of 128761111 in words is "one hundred twenty-eight million, seven hundred sixty-one thousand, one hundred eleven".