77778325720 has 32 divisors (see below), whose sum is σ = 177870111120. Its totient is φ = 30601307520.

The previous prime is 77778325697. The next prime is 77778325721. The reversal of 77778325720 is 2752387777.

It is a Smith number, since the sum of its digits (55) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77778325721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15935742 + ... + 15940621.

Almost surely, 2^77778325720 is an apocalyptic number.

It is an amenable number.

77778325720 is an abundant number, since it is smaller than the sum of its proper divisors (100091785400).

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

77778325720 is a wasteful number, since it uses less digits than its factorization.

77778325720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31876435 (or 31876431 counting only the distinct ones).

The product of its (nonzero) digits is 8067360, while the sum is 55.

The spelling of 77778325720 in words is "seventy-seven billion, seven hundred seventy-eight million, three hundred twenty-five thousand, seven hundred twenty".