78656818 has 4 divisors (see below), whose sum is σ = 117985230. Its totient is φ = 39328408.

The previous prime is 78656813. The next prime is 78656863. The reversal of 78656818 is 81865687.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81865687 = 3761 ⋅21767.

It can be written as a sum of positive squares in only one way, i.e., 59182249 + 19474569 = 7693^2 + 4413^2 .

It is not an unprimeable number, because it can be changed into a prime (78656813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19664203 + ... + 19664206.

Almost surely, 2^78656818 is an apocalyptic number.

78656818 is a deficient number, since it is larger than the sum of its proper divisors (39328412).

78656818 is a wasteful number, since it uses less digits than its factorization.

78656818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39328411.

The product of its digits is 645120, while the sum is 49.

The square root of 78656818 is about 8868.8679097165. The cubic root of 78656818 is about 428.4618162746.

The spelling of 78656818 in words is "seventy-eight million, six hundred fifty-six thousand, eight hundred eighteen".