78936721728 has 28 divisors (see below), whose sum is σ = 208853410080. Its totient is φ = 26312240512.

The previous prime is 78936721727. The next prime is 78936721733. The reversal of 78936721728 is 82712763987.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78936721727) 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, 205564188 + ... + 205564571.

It is an arithmetic number, because the mean of its divisors is an integer number (7459050360).

Almost surely, 2^78936721728 is an apocalyptic number.

It is an amenable number.

78936721728 is an abundant number, since it is smaller than the sum of its proper divisors (129916688352).

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

78936721728 is a wasteful number, since it uses less digits than its factorization.

78936721728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411128774 (or 411128764 counting only the distinct ones).

The product of its digits is 14224896, while the sum is 60.

The spelling of 78936721728 in words is "seventy-eight billion, nine hundred thirty-six million, seven hundred twenty-one thousand, seven hundred twenty-eight".