778823640 has 192 divisors, whose sum is σ = 3020133600. Its totient is φ = 178004736.

The previous prime is 778823629. The next prime is 778823651. The reversal of 778823640 is 46328877.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (778823629) and next prime (778823651).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 45562 + ... + 60278.

Almost surely, 2^778823640 is an apocalyptic number.

778823640 is a gapful number since it is divisible by the number (70) 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 778823640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1510066800).

778823640 is an abundant number, since it is smaller than the sum of its proper divisors (2241309960).

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

778823640 is a wasteful number, since it uses less digits than its factorization.

778823640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14751 (or 14734 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 45.

The square root of 778823640 is about 27907.4119187000. The cubic root of 778823640 is about 920.0534152981.

The spelling of 778823640 in words is "seven hundred seventy-eight million, eight hundred twenty-three thousand, six hundred forty".