1128778285 has 4 divisors (see below), whose sum is σ = 1354533948. Its totient is φ = 903022624.

The previous prime is 1128778253. The next prime is 1128778297. The reversal of 1128778285 is 5828778211.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5828778211 = 1399 ⋅4166389.

It can be written as a sum of positive squares in 2 ways, for example, as 497914596 + 630863689 = 22314^2 + 25117^2 .

It is a cyclic number.

It is not a de Polignac number, because 1128778285 - 2⁵ = 1128778253 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112877824 + ... + 112877833.

It is an arithmetic number, because the mean of its divisors is an integer number (338633487).

Almost surely, 2^1128778285 is an apocalyptic number.

It is an amenable number.

1128778285 is a deficient number, since it is larger than the sum of its proper divisors (225755663).

1128778285 is an equidigital number, since it uses as much as digits as its factorization.

1128778285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225755662.

The product of its digits is 501760, while the sum is 49.

The square root of 1128778285 is about 33597.2957989181. The cubic root of 1128778285 is about 1041.2049289530.

The spelling of 1128778285 in words is "one billion, one hundred twenty-eight million, seven hundred seventy-eight thousand, two hundred eighty-five".