78909988787 has 8 divisors (see below), whose sum is σ = 90210799200. Its totient is φ = 67616167104.

The previous prime is 78909988777. The next prime is 78909988849. The reversal of 78909988787 is 78788990987.

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

It is a cyclic number.

It is not a de Polignac number, because 78909988787 - 2⁶ = 78909988723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78909988747) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1722962 + ... + 1768167.

It is an arithmetic number, because the mean of its divisors is an integer number (11276349900).

Almost surely, 2^78909988787 is an apocalyptic number.

78909988787 is a deficient number, since it is larger than the sum of its proper divisors (11300810413).

78909988787 is a wasteful number, since it uses less digits than its factorization.

78909988787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3494365.

The product of its (nonzero) digits is 1024192512, while the sum is 80.

The spelling of 78909988787 in words is "seventy-eight billion, nine hundred nine million, nine hundred eighty-eight thousand, seven hundred eighty-seven".