78916549 has 4 divisors (see below), whose sum is σ = 79016364. Its totient is φ = 78816736.

The previous prime is 78916547. The next prime is 78916559. The reversal of 78916549 is 94561987.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94561987 = 13 ⋅7273999.

It can be written as a sum of positive squares in 2 ways, for example, as 11512449 + 67404100 = 3393^2 + 8210^2 .

It is a cyclic number.

It is not a de Polignac number, because 78916549 - 2¹ = 78916547 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78916547) 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, 48712 + ... + 50305.

It is an arithmetic number, because the mean of its divisors is an integer number (19754091).

Almost surely, 2^78916549 is an apocalyptic number.

It is an amenable number.

78916549 is a deficient number, since it is larger than the sum of its proper divisors (99815).

78916549 is an equidigital number, since it uses as much as digits as its factorization.

78916549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99814.

The product of its digits is 544320, while the sum is 49.

The square root of 78916549 is about 8883.4986913941. The cubic root of 78916549 is about 428.9329030057.

The spelling of 78916549 in words is "seventy-eight million, nine hundred sixteen thousand, five hundred forty-nine".