128426778 has 24 divisors (see below), whose sum is σ = 285779988. Its totient is φ = 41651712.

The previous prime is 128426747. The next prime is 128426797. The reversal of 128426778 is 877624821.

It can be written as a sum of positive squares in 2 ways, for example, as 125283249 + 3143529 = 11193^2 + 1773^2 .

It is a super-2 number, since 2×128426778² = 32986874614922568, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 95751 + ... + 97082.

Almost surely, 2^128426778 is an apocalyptic number.

128426778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

128426778 is an abundant number, since it is smaller than the sum of its proper divisors (157353210).

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

128426778 is a wasteful number, since it uses less digits than its factorization.

128426778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192878 (or 192875 counting only the distinct ones).

The product of its digits is 301056, while the sum is 45.

The square root of 128426778 is about 11332.5539045707. The cubic root of 128426778 is about 504.5279096274.

The spelling of 128426778 in words is "one hundred twenty-eight million, four hundred twenty-six thousand, seven hundred seventy-eight".