78578249 has 2 divisors, whose sum is σ = 78578250. Its totient is φ = 78578248.

The previous prime is 78578239. The next prime is 78578251. The reversal of 78578249 is 94287587.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48052624 + 30525625 = 6932^2 + 5525^2 .

It is an emirp because it is prime and its reverse (94287587) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78578249 is a prime.

It is a Sophie Germain prime.

Together with 78578251, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 78578197 and 78578206.

It is not a weakly prime, because it can be changed into another prime (78578239) 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, 39289124 + 39289125.

It is an arithmetic number, because the mean of its divisors is an integer number (39289125).

Almost surely, 2^78578249 is an apocalyptic number.

It is an amenable number.

78578249 is a deficient number, since it is larger than the sum of its proper divisors (1).

78578249 is an equidigital number, since it uses as much as digits as its factorization.

78578249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1128960, while the sum is 50.

The square root of 78578249 is about 8864.4373199882. The cubic root of 78578249 is about 428.3191075971.

The spelling of 78578249 in words is "seventy-eight million, five hundred seventy-eight thousand, two hundred forty-nine".