78718479509 has 4 divisors (see below), whose sum is σ = 79827190560. Its totient is φ = 77609768460.

The previous prime is 78718479479. The next prime is 78718479517. The reversal of 78718479509 is 90597481787.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 78718479509 - 2²⁰ = 78717430933 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78718479589) 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, 554355419 + ... + 554355560.

It is an arithmetic number, because the mean of its divisors is an integer number (19956797640).

Almost surely, 2^78718479509 is an apocalyptic number.

It is an amenable number.

78718479509 is a deficient number, since it is larger than the sum of its proper divisors (1108711051).

78718479509 is a wasteful number, since it uses less digits than its factorization.

78718479509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1108711050.

The product of its (nonzero) digits is 35562240, while the sum is 65.

The spelling of 78718479509 in words is "seventy-eight billion, seven hundred eighteen million, four hundred seventy-nine thousand, five hundred nine".