128778396 has 12 divisors (see below), whose sum is σ = 300482952. Its totient is φ = 42926128.

The previous prime is 128778361. The next prime is 128778437. The reversal of 128778396 is 693877821.

It is a tau number, because it is divible by the number of its divisors (12).

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, 5365755 + ... + 5365778.

It is an arithmetic number, because the mean of its divisors is an integer number (25040246).

Almost surely, 2^128778396 is an apocalyptic number.

It is an amenable number.

128778396 is an abundant number, since it is smaller than the sum of its proper divisors (171704556).

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

128778396 is a wasteful number, since it uses less digits than its factorization.

128778396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10731540 (or 10731538 counting only the distinct ones).

The product of its digits is 1016064, while the sum is 51.

The square root of 128778396 is about 11348.0569261878. The cubic root of 128778396 is about 504.9879368422.

The spelling of 128778396 in words is "one hundred twenty-eight million, seven hundred seventy-eight thousand, three hundred ninety-six".