128866111 has 8 divisors (see below), whose sum is σ = 145429200. Its totient is φ = 113111040.

The previous prime is 128866093. The next prime is 128866117. The reversal of 128866111 is 111668821.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128866111 - 2²¹ = 126768959 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128866117) 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 7 ways as a sum of consecutive naturals, for example, 201666 + ... + 202303.

It is an arithmetic number, because the mean of its divisors is an integer number (18178650).

Almost surely, 2^128866111 is an apocalyptic number.

128866111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

128866111 is a deficient number, since it is larger than the sum of its proper divisors (16563089).

128866111 is a wasteful number, since it uses less digits than its factorization.

128866111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404009.

The product of its digits is 4608, while the sum is 34.

The square root of 128866111 is about 11351.9210268571. The cubic root of 128866111 is about 505.1025651886.

The spelling of 128866111 in words is "one hundred twenty-eight million, eight hundred sixty-six thousand, one hundred eleven".