2778128 has 20 divisors (see below), whose sum is σ = 5408508. Its totient is φ = 1382400.

The previous prime is 2778121. The next prime is 2778131. The reversal of 2778128 is 8218772.

It can be written as a sum of positive squares in 2 ways, for example, as 1721344 + 1056784 = 1312^2 + 1028^2 .

It is not an unprimeable number, because it can be changed into a prime (2778121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6200 + ... + 6632.

2^2778128 is an apocalyptic number.

It is an amenable number.

2778128 is a deficient number, since it is larger than the sum of its proper divisors (2630380).

2778128 is a wasteful number, since it uses less digits than its factorization.

2778128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842 (or 836 counting only the distinct ones).

The product of its digits is 12544, while the sum is 35.

The square root of 2778128 is about 1666.7717300218. The cubic root of 2778128 is about 140.5780184126.

The spelling of 2778128 in words is "two million, seven hundred seventy-eight thousand, one hundred twenty-eight".