128778 has 24 divisors (see below), whose sum is σ = 281088. Its totient is φ = 39312.

The previous prime is 128767. The next prime is 128813. The reversal of 128778 is 877821.

128778 is a nontrivial binomial coefficient, being equal to C(508, 2).

It is a nialpdrome in base 11.

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, 951 + ... + 1077.

It is an arithmetic number, because the mean of its divisors is an integer number (11712).

2¹²⁸⁷⁷⁸ is an apocalyptic number.

128778 is the 507-th triangular number and also the 254-th hexagonal number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140544).

128778 is an abundant number, since it is smaller than the sum of its proper divisors (152310).

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

128778 is a wasteful number, since it uses less digits than its factorization.

128778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158 (or 145 counting only the distinct ones).

The product of its digits is 6272, while the sum is 33.

The square root of 128778 is about 358.8565172879. The cubic root of 128778 is about 50.4987419221.

The spelling of 128778 in words is "one hundred twenty-eight thousand, seven hundred seventy-eight".