128870911 has 4 divisors (see below), whose sum is σ = 138784072. Its totient is φ = 118957752.

The previous prime is 128870887. The next prime is 128870921. The reversal of 128870911 is 119078821.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128870911 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 (128870921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4956561 + ... + 4956586.

It is an arithmetic number, because the mean of its divisors is an integer number (34696018).

Almost surely, 2^128870911 is an apocalyptic number.

128870911 is a deficient number, since it is larger than the sum of its proper divisors (9913161).

128870911 is an equidigital number, since it uses as much as digits as its factorization.

128870911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9913160.

The product of its (nonzero) digits is 8064, while the sum is 37.

The square root of 128870911 is about 11352.1324428497. The cubic root of 128870911 is about 505.1088364578.

The spelling of 128870911 in words is "one hundred twenty-eight million, eight hundred seventy thousand, nine hundred eleven".