1278555426 has 12 divisors (see below), whose sum is σ = 2770203462. Its totient is φ = 426185136.

The previous prime is 1278555419. The next prime is 1278555427. The reversal of 1278555426 is 6245558721.

1278555426 is a `hidden beast` number, since 1 + 2 + 78 + 5 + 554 + 26 = 666.

It can be written as a sum of positive squares in only one way, i.e., 678550401 + 600005025 = 26049^2 + 24495^2 .

It is not an unprimeable number, because it can be changed into a prime (1278555427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35515411 + ... + 35515446.

Almost surely, 2^1278555426 is an apocalyptic number.

1278555426 is an abundant number, since it is smaller than the sum of its proper divisors (1491648036).

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

1278555426 is a wasteful number, since it uses less digits than its factorization.

1278555426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71030865 (or 71030862 counting only the distinct ones).

The product of its digits is 672000, while the sum is 45.

The square root of 1278555426 is about 35756.8934053282. The cubic root of 1278555426 is about 1085.3584369347.

The spelling of 1278555426 in words is "one billion, two hundred seventy-eight million, five hundred fifty-five thousand, four hundred twenty-six".