777680 has 20 divisors (see below), whose sum is σ = 1808292. Its totient is φ = 311040.

The previous prime is 777677. The next prime is 777683. The reversal of 777680 is 86777.

It is an interprime number because it is at equal distance from previous prime (777677) and next prime (777683).

It can be written as a sum of positive squares in 2 ways, for example, as 118336 + 659344 = 344^2 + 812^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 777680.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 777680.

It is not an unprimeable number, because it can be changed into a prime (777683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4781 + ... + 4940.

2⁷⁷⁷⁶⁸⁰ is an apocalyptic number.

It is an amenable number.

777680 is an abundant number, since it is smaller than the sum of its proper divisors (1030612).

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

777680 is a wasteful number, since it uses less digits than its factorization.

777680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9734 (or 9728 counting only the distinct ones).

The product of its (nonzero) digits is 16464, while the sum is 35.

The square root of 777680 is about 881.8616671565. The cubic root of 777680 is about 91.9602853158.

The spelling of 777680 in words is "seven hundred seventy-seven thousand, six hundred eighty".