78909988786 has 8 divisors (see below), whose sum is σ = 118391411484. Its totient is φ = 39446184960.

The previous prime is 78909988777. The next prime is 78909988849. The reversal of 78909988786 is 68788990987.

It can be written as a sum of positive squares in 2 ways, for example, as 75305787561 + 3604201225 = 274419^2 + 60035^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4393515 + ... + 4411438.

Almost surely, 2^78909988786 is an apocalyptic number.

78909988786 is a deficient number, since it is larger than the sum of its proper divisors (39481422698).

78909988786 is a wasteful number, since it uses less digits than its factorization.

78909988786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8809436.

The product of its (nonzero) digits is 877879296, while the sum is 79.

The spelling of 78909988786 in words is "seventy-eight billion, nine hundred nine million, nine hundred eighty-eight thousand, seven hundred eighty-six".