777216 has 88 divisors (see below), whose sum is σ = 2358144. Its totient is φ = 225280.

The previous prime is 777209. The next prime is 777221. The reversal of 777216 is 612777.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (88).

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

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 777216.

It is an unprimeable number.

777216 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33781 + ... + 33803.

2⁷⁷⁷²¹⁶ 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 777216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1179072).

777216 is an abundant number, since it is smaller than the sum of its proper divisors (1580928).

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

777216 is a wasteful number, since it uses less digits than its factorization.

777216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57 (or 39 counting only the distinct ones).

The product of its digits is 4116, while the sum is 30.

The square root of 777216 is about 881.5985480932. The cubic root of 777216 is about 91.9419924184.

The spelling of 777216 in words is "seven hundred seventy-seven thousand, two hundred sixteen".