128555407 has 4 divisors (see below), whose sum is σ = 128617920. Its totient is φ = 128492896.

The previous prime is 128555389. The next prime is 128555417. The reversal of 128555407 is 704555821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 704555821 = 173 ⋅4072577.

It is a cyclic number.

It is not a de Polignac number, because 128555407 - 2¹⁹ = 128031119 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 (128555417) 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, 28063 + ... + 32320.

It is an arithmetic number, because the mean of its divisors is an integer number (32154480).

Almost surely, 2^128555407 is an apocalyptic number.

128555407 is a deficient number, since it is larger than the sum of its proper divisors (62513).

128555407 is an equidigital number, since it uses as much as digits as its factorization.

128555407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62512.

The product of its (nonzero) digits is 56000, while the sum is 37.

The square root of 128555407 is about 11338.2276833727. The cubic root of 128555407 is about 504.6962942047.

The spelling of 128555407 in words is "one hundred twenty-eight million, five hundred fifty-five thousand, four hundred seven".