778087128 has 128 divisors (see below), whose sum is σ = 2421619200. Its totient is φ = 202853376.

The previous prime is 778087109. The next prime is 778087129. The reversal of 778087128 is 821780877.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (778087129) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 192375 + ... + 196377.

It is an arithmetic number, because the mean of its divisors is an integer number (18918900).

Almost surely, 2^778087128 is an apocalyptic number.

778087128 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 778087128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1210809600).

778087128 is an abundant number, since it is smaller than the sum of its proper divisors (1643532072).

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

778087128 is a wasteful number, since it uses less digits than its factorization.

778087128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4121 (or 4117 counting only the distinct ones).

The product of its (nonzero) digits is 351232, while the sum is 48.

The square root of 778087128 is about 27894.2131633068. The cubic root of 778087128 is about 919.7633007956.

The spelling of 778087128 in words is "seven hundred seventy-eight million, eighty-seven thousand, one hundred twenty-eight".