78086609 has 2 divisors, whose sum is σ = 78086610. Its totient is φ = 78086608.

The previous prime is 78086549. The next prime is 78086621. The reversal of 78086609 is 90668087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60109009 + 17977600 = 7753^2 + 4240^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78086609 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 78086609.

It is not a weakly prime, because it can be changed into another prime (78026609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39043304 + 39043305.

It is an arithmetic number, because the mean of its divisors is an integer number (39043305).

Almost surely, 2^78086609 is an apocalyptic number.

It is an amenable number.

78086609 is a deficient number, since it is larger than the sum of its proper divisors (1).

78086609 is an equidigital number, since it uses as much as digits as its factorization.

78086609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 78086609 is about 8836.6627750526. The cubic root of 78086609 is about 427.4239509970.

The spelling of 78086609 in words is "seventy-eight million, eighty-six thousand, six hundred nine".