778400 has 72 divisors (see below), whose sum is σ = 2187360. Its totient is φ = 264960.

The previous prime is 778397. The next prime is 778403. The reversal of 778400 is 4877.

It is an interprime number because it is at equal distance from previous prime (778397) and next prime (778403).

It is a self number, because there is not a number n which added to its sum of digits gives 778400.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 778400.

It is not an unprimeable number, because it can be changed into a prime (778403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5531 + ... + 5669.

It is an arithmetic number, because the mean of its divisors is an integer number (30380).

2⁷⁷⁸⁴⁰⁰ is an apocalyptic number.

778400 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 778400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1093680).

778400 is an abundant number, since it is smaller than the sum of its proper divisors (1408960).

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

778400 is a wasteful number, since it uses less digits than its factorization.

778400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 153 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 26.

The square root of 778400 is about 882.2698000045. The cubic root of 778400 is about 91.9886564464.

The spelling of 778400 in words is "seven hundred seventy-eight thousand, four hundred".