78656117 has 4 divisors (see below), whose sum is σ = 80781996. Its totient is φ = 76530240.

The previous prime is 78656107. The next prime is 78656119. The reversal of 78656117 is 71165687.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71165687 = 103 ⋅690929.

It can be written as a sum of positive squares in 2 ways, for example, as 48636676 + 30019441 = 6974^2 + 5479^2 .

It is a cyclic number.

It is not a de Polignac number, because 78656117 - 2⁴ = 78656101 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 (78656119) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1062884 + ... + 1062957.

It is an arithmetic number, because the mean of its divisors is an integer number (20195499).

Almost surely, 2^78656117 is an apocalyptic number.

It is an amenable number.

78656117 is a deficient number, since it is larger than the sum of its proper divisors (2125879).

78656117 is a wasteful number, since it uses less digits than its factorization.

78656117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2125878.

The product of its digits is 70560, while the sum is 41.

The square root of 78656117 is about 8868.8283893646. The cubic root of 78656117 is about 428.4605434346.

The spelling of 78656117 in words is "seventy-eight million, six hundred fifty-six thousand, one hundred seventeen".