78909199 has 2 divisors, whose sum is σ = 78909200. Its totient is φ = 78909198.

The previous prime is 78909191. The next prime is 78909217. The reversal of 78909199 is 99190987.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78909199 - 2³ = 78909191 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78909191) 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, 39454599 + 39454600.

It is an arithmetic number, because the mean of its divisors is an integer number (39454600).

Almost surely, 2^78909199 is an apocalyptic number.

78909199 is a deficient number, since it is larger than the sum of its proper divisors (1).

78909199 is an equidigital number, since it uses as much as digits as its factorization.

78909199 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 367416, while the sum is 52.

The square root of 78909199 is about 8883.0849934018. The cubic root of 78909199 is about 428.9195861761.

The spelling of 78909199 in words is "seventy-eight million, nine hundred nine thousand, one hundred ninety-nine".