778228866 has 48 divisors (see below), whose sum is σ = 1793282400. Its totient is φ = 243212544.

The previous prime is 778228861. The next prime is 778228879. The reversal of 778228866 is 668822877.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (778228861) 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 23 ways as a sum of consecutive naturals, for example, 21445 + ... + 44903.

It is an arithmetic number, because the mean of its divisors is an integer number (37360050).

Almost surely, 2^778228866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 778228866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (896641200).

778228866 is an abundant number, since it is smaller than the sum of its proper divisors (1015053534).

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

778228866 is a wasteful number, since it uses less digits than its factorization.

778228866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23583 (or 23580 counting only the distinct ones).

The product of its digits is 3612672, while the sum is 54.

The square root of 778228866 is about 27896.7536821043. The cubic root of 778228866 is about 919.8191460820.

The spelling of 778228866 in words is "seven hundred seventy-eight million, two hundred twenty-eight thousand, eight hundred sixty-six".