78767257 has 2 divisors, whose sum is σ = 78767258. Its totient is φ = 78767256.

The previous prime is 78767243. The next prime is 78767261. The reversal of 78767257 is 75276787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72522256 + 6245001 = 8516^2 + 2499^2 .

It is an emirp because it is prime and its reverse (75276787) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78767257 - 2¹¹ = 78765209 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78767257.

It is not a weakly prime, because it can be changed into another prime (78767207) 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 as a sum of consecutive naturals, namely, 39383628 + 39383629.

It is an arithmetic number, because the mean of its divisors is an integer number (39383629).

Almost surely, 2^78767257 is an apocalyptic number.

It is an amenable number.

78767257 is a deficient number, since it is larger than the sum of its proper divisors (1).

78767257 is an equidigital number, since it uses as much as digits as its factorization.

78767257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152480, while the sum is 49.

The square root of 78767257 is about 8875.0919431857. The cubic root of 78767257 is about 428.6622513917.

The spelling of 78767257 in words is "seventy-eight million, seven hundred sixty-seven thousand, two hundred fifty-seven".