78561566117 has 8 divisors (see below), whose sum is σ = 79814427000. Its totient is φ = 77318380224.

The previous prime is 78561566113. The next prime is 78561566129. The reversal of 78561566117 is 71166516587.

It can be written as a sum of positive squares in 4 ways, for example, as 385965316 + 78175600801 = 19646^2 + 279599^2 .

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 78561566117 - 2² = 78561566113 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78561566113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2402378 + ... + 2434859.

It is an arithmetic number, because the mean of its divisors is an integer number (9976803375).

Almost surely, 2^78561566117 is an apocalyptic number.

It is an amenable number.

78561566117 is a deficient number, since it is larger than the sum of its proper divisors (1252860883).

78561566117 is a wasteful number, since it uses less digits than its factorization.

78561566117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4837495.

The product of its digits is 2116800, while the sum is 53.

The spelling of 78561566117 in words is "seventy-eight billion, five hundred sixty-one million, five hundred sixty-six thousand, one hundred seventeen".