778680 has 128 divisors (see below), whose sum is σ = 2995200. Its totient is φ = 176256.

The previous prime is 778667. The next prime is 778681. The reversal of 778680 is 86877.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (778681) by changing a digit.

778680 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7509 + ... + 7611.

It is an arithmetic number, because the mean of its divisors is an integer number (23400).

2⁷⁷⁸⁶⁸⁰ is an apocalyptic number.

778680 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 778680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1497600).

778680 is an abundant number, since it is smaller than the sum of its proper divisors (2216520).

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

778680 is a wasteful number, since it uses less digits than its factorization.

778680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 778680 is about 882.4284673559. The cubic root of 778680 is about 91.9996849391. Note that the first 3 decimals are identical.

It can be divided in two parts, 7 and 78680, that added together give a palindrome (78687).

The spelling of 778680 in words is "seven hundred seventy-eight thousand, six hundred eighty".