128005556306 has 4 divisors (see below), whose sum is σ = 192008334462. Its totient is φ = 64002778152.

The previous prime is 128005556293. The next prime is 128005556311. The reversal of 128005556306 is 603655500821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 603655500821 = 31 ⋅19472758091.

It can be written as a sum of positive squares in only one way, i.e., 126351100681 + 1654455625 = 355459^2 + 40675^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32001389075 + ... + 32001389078.

Almost surely, 2^128005556306 is an apocalyptic number.

128005556306 is a deficient number, since it is larger than the sum of its proper divisors (64002778156).

128005556306 is an equidigital number, since it uses as much as digits as its factorization.

128005556306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64002778155.

The product of its (nonzero) digits is 216000, while the sum is 41.

The spelling of 128005556306 in words is "one hundred twenty-eight billion, five million, five hundred fifty-six thousand, three hundred six".