78317426909 has 2 divisors, whose sum is σ = 78317426910. Its totient is φ = 78317426908.

The previous prime is 78317426867. The next prime is 78317426917. The reversal of 78317426909 is 90962471387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63743625625 + 14573801284 = 252475^2 + 120722^2 .

It is a cyclic number.

It is not a de Polignac number, because 78317426909 - 2¹⁶ = 78317361373 is a prime.

It is a super-2 number, since 2×78317426909² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78317426959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39158713454 + 39158713455.

It is an arithmetic number, because the mean of its divisors is an integer number (39158713455).

Almost surely, 2^78317426909 is an apocalyptic number.

It is an amenable number.

78317426909 is a deficient number, since it is larger than the sum of its proper divisors (1).

78317426909 is an equidigital number, since it uses as much as digits as its factorization.

78317426909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4572288, while the sum is 56.

The spelling of 78317426909 in words is "seventy-eight billion, three hundred seventeen million, four hundred twenty-six thousand, nine hundred nine".