78869191 has 2 divisors, whose sum is σ = 78869192. Its totient is φ = 78869190.

The previous prime is 78869179. The next prime is 78869201. The reversal of 78869191 is 19196887.

It is a strong prime.

It is an emirp because it is prime and its reverse (19196887) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78869191 is a prime.

It is a plaindrome in base 13.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78869111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39434595 + 39434596.

It is an arithmetic number, because the mean of its divisors is an integer number (39434596).

Almost surely, 2^78869191 is an apocalyptic number.

78869191 is a deficient number, since it is larger than the sum of its proper divisors (1).

78869191 is an equidigital number, since it uses as much as digits as its factorization.

78869191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 217728, while the sum is 49.

The square root of 78869191 is about 8880.8327875262. The cubic root of 78869191 is about 428.8470846342.

The spelling of 78869191 in words is "seventy-eight million, eight hundred sixty-nine thousand, one hundred ninety-one".