78109917517 has 8 divisors (see below), whose sum is σ = 78321116160. Its totient is φ = 77898858480.

The previous prime is 78109917497. The next prime is 78109917521. The reversal of 78109917517 is 71571990187.

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 78109917517 - 2³⁵ = 43750179149 is a prime.

It is a super-2 number, since 2×78109917517² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78109417517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1138563 + ... + 1205215.

It is an arithmetic number, because the mean of its divisors is an integer number (9790139520).

Almost surely, 2^78109917517 is an apocalyptic number.

It is an amenable number.

78109917517 is a deficient number, since it is larger than the sum of its proper divisors (211198643).

78109917517 is a wasteful number, since it uses less digits than its factorization.

78109917517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69803.

The product of its (nonzero) digits is 1111320, while the sum is 55.

The spelling of 78109917517 in words is "seventy-eight billion, one hundred nine million, nine hundred seventeen thousand, five hundred seventeen".