2128256189478 has 32 divisors (see below), whose sum is σ = 4772847736800. Its totient is φ = 702910299168.

The previous prime is 2128256189443. The next prime is 2128256189491. The reversal of 2128256189478 is 8749816528212.

2128256189478 is a `hidden beast` number, since 2 + 1 + 2 + 8 + 2 + 5 + 618 + 9 + 4 + 7 + 8 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 180783801 + ... + 180795572.

It is an arithmetic number, because the mean of its divisors is an integer number (149151491775).

Almost surely, 2^{2128256189478} is an apocalyptic number.

2128256189478 is an abundant number, since it is smaller than the sum of its proper divisors (2644591547322).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2128256189478 is a wasteful number, since it uses less digits than its factorization.

2128256189478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361579493 (or 361579487 counting only the distinct ones).

The product of its digits is 30965760, while the sum is 63.

The spelling of 2128256189478 in words is "two trillion, one hundred twenty-eight billion, two hundred fifty-six million, one hundred eighty-nine thousand, four hundred seventy-eight".