78218425775855 has 4 divisors (see below), whose sum is σ = 93862110931032. Its totient is φ = 62574740620680.

The previous prime is 78218425775807. The next prime is 78218425775863. The reversal of 78218425775855 is 55857752481287.

It is a happy number.

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

It is not a de Polignac number, because 78218425775855 - 2⁸ = 78218425775599 is a prime.

It is a super-2 number, since 2×78218425775855² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7821842577581 + ... + 7821842577590.

It is an arithmetic number, because the mean of its divisors is an integer number (23465527732758).

Almost surely, 2^{78218425775855} is an apocalyptic number.

78218425775855 is a deficient number, since it is larger than the sum of its proper divisors (15643685155177).

78218425775855 is a wasteful number, since it uses less digits than its factorization.

78218425775855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15643685155176.

The product of its digits is 1756160000, while the sum is 74.

The spelling of 78218425775855 in words is "seventy-eight trillion, two hundred eighteen billion, four hundred twenty-five million, seven hundred seventy-five thousand, eight hundred fifty-five".