77778648 has 24 divisors (see below), whose sum is σ = 210650700. Its totient is φ = 25926192.

The previous prime is 77778641. The next prime is 77778661. The reversal of 77778648 is 84687777.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (24).

It is a junction number, because it is equal to n+sod(n) for n = 77778594 and 77778603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77778641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 540058 + ... + 540201.

Almost surely, 2^77778648 is an apocalyptic number.

It is an amenable number.

77778648 is an abundant number, since it is smaller than the sum of its proper divisors (132872052).

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

77778648 is a wasteful number, since it uses less digits than its factorization.

77778648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080271 (or 1080264 counting only the distinct ones).

The product of its digits is 3687936, while the sum is 54.

The square root of 77778648 is about 8819.2203737065. The cubic root of 77778648 is about 426.8613136401.

The spelling of 77778648 in words is "seventy-seven million, seven hundred seventy-eight thousand, six hundred forty-eight".