78683909 has 2 divisors, whose sum is σ = 78683910. Its totient is φ = 78683908.

The previous prime is 78683827. The next prime is 78683911. The reversal of 78683909 is 90938687.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46444225 + 32239684 = 6815^2 + 5678^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78683909 is a prime.

Together with 78683911, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78683509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39341954 + 39341955.

It is an arithmetic number, because the mean of its divisors is an integer number (39341955).

Almost surely, 2^78683909 is an apocalyptic number.

It is an amenable number.

78683909 is a deficient number, since it is larger than the sum of its proper divisors (1).

78683909 is an equidigital number, since it uses as much as digits as its factorization.

78683909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 653184, while the sum is 50.

The square root of 78683909 is about 8870.3950870297. The cubic root of 78683909 is about 428.5110009353.

The spelling of 78683909 in words is "seventy-eight million, six hundred eighty-three thousand, nine hundred nine".