78786397 has 2 divisors, whose sum is σ = 78786398. Its totient is φ = 78786396.

The previous prime is 78786391. The next prime is 78786419. The reversal of 78786397 is 79368787.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73719396 + 5067001 = 8586^2 + 2251^2 .

It is an emirp because it is prime and its reverse (79368787) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78786397 - 2⁷ = 78786269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78786391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39393198 + 39393199.

It is an arithmetic number, because the mean of its divisors is an integer number (39393199).

Almost surely, 2^78786397 is an apocalyptic number.

It is an amenable number.

78786397 is a deficient number, since it is larger than the sum of its proper divisors (1).

78786397 is an equidigital number, since it uses as much as digits as its factorization.

78786397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3556224, while the sum is 55.

The square root of 78786397 is about 8876.1701763767. The cubic root of 78786397 is about 428.6969694177.

The spelling of 78786397 in words is "seventy-eight million, seven hundred eighty-six thousand, three hundred ninety-seven".