78680813 has 4 divisors (see below), whose sum is σ = 78800508. Its totient is φ = 78561120.

The previous prime is 78680783. The next prime is 78680837. The reversal of 78680813 is 31808687.

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 57123364 + 21557449 = 7558^2 + 4643^2 .

It is a cyclic number.

It is not a de Polignac number, because 78680813 - 2²⁰ = 77632237 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 (78680873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58856 + ... + 60177.

It is an arithmetic number, because the mean of its divisors is an integer number (19700127).

Almost surely, 2^78680813 is an apocalyptic number.

It is an amenable number.

78680813 is a deficient number, since it is larger than the sum of its proper divisors (119695).

78680813 is a wasteful number, since it uses less digits than its factorization.

78680813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119694.

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 78680813 is about 8870.2205722293. The cubic root of 78680813 is about 428.5053806101.

The spelling of 78680813 in words is "seventy-eight million, six hundred eighty thousand, eight hundred thirteen".