778993440 has 192 divisors, whose sum is σ = 2624493312. Its totient is φ = 193740800.

The previous prime is 778993421. The next prime is 778993459. The reversal of 778993440 is 44399877.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (778993421) and next prime (778993459).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 451780 + ... + 453500.

It is an arithmetic number, because the mean of its divisors is an integer number (13669236).

Almost surely, 2^778993440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 778993440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1312246656).

778993440 is an abundant number, since it is smaller than the sum of its proper divisors (1845499872).

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

778993440 is a wasteful number, since it uses less digits than its factorization.

778993440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1803 (or 1795 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 51.

The square root of 778993440 is about 27910.4539554626. The cubic root of 778993440 is about 920.1202741306.

The spelling of 778993440 in words is "seven hundred seventy-eight million, nine hundred ninety-three thousand, four hundred forty".