78451384309 has 2 divisors, whose sum is σ = 78451384310. Its totient is φ = 78451384308.

The previous prime is 78451384267. The next prime is 78451384337. The reversal of 78451384309 is 90348315487.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75777977284 + 2673407025 = 275278^2 + 51705^2 .

It is an emirp because it is prime and its reverse (90348315487) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78451384309 - 2⁹ = 78451383797 is a prime.

It is a super-2 number, since 2×78451384309² (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 (78451384709) 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, 39225692154 + 39225692155.

It is an arithmetic number, because the mean of its divisors is an integer number (39225692155).

Almost surely, 2^78451384309 is an apocalyptic number.

It is an amenable number.

78451384309 is a deficient number, since it is larger than the sum of its proper divisors (1).

78451384309 is an equidigital number, since it uses as much as digits as its factorization.

78451384309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2903040, while the sum is 52.

The spelling of 78451384309 in words is "seventy-eight billion, four hundred fifty-one million, three hundred eighty-four thousand, three hundred nine".