78105750881617 has 4 divisors (see below), whose sum is σ = 78105768736180. Its totient is φ = 78105733027056.

The previous prime is 78105750881603. The next prime is 78105750881623. The reversal of 78105750881617 is 71618805750187.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 38222181043281 + 39883569838336 = 6182409^2 + 6315344^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78105750881617 is a prime.

It is a super-2 number, since 2×78105750881617² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78105750881317) 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 3 ways as a sum of consecutive naturals, for example, 2571859 + ... + 12760327.

It is an arithmetic number, because the mean of its divisors is an integer number (19526442184045).

Almost surely, 2^{78105750881617} is an apocalyptic number.

It is an amenable number.

78105750881617 is a deficient number, since it is larger than the sum of its proper divisors (17854563).

78105750881617 is a wasteful number, since it uses less digits than its factorization.

78105750881617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17854562.

The product of its (nonzero) digits is 26342400, while the sum is 64.

The spelling of 78105750881617 in words is "seventy-eight trillion, one hundred five billion, seven hundred fifty million, eight hundred eighty-one thousand, six hundred seventeen".