78294247309 has 2 divisors, whose sum is σ = 78294247310. Its totient is φ = 78294247308.

The previous prime is 78294247301. The next prime is 78294247331. The reversal of 78294247309 is 90374249287.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39565188100 + 38729059209 = 198910^2 + 196797^2 .

It is a cyclic number.

It is not a de Polignac number, because 78294247309 - 2³ = 78294247301 is a prime.

It is a super-2 number, since 2×78294247309² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78294247309.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78294247301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39147123654 + 39147123655.

It is an arithmetic number, because the mean of its divisors is an integer number (39147123655).

Almost surely, 2^78294247309 is an apocalyptic number.

It is an amenable number.

78294247309 is a deficient number, since it is larger than the sum of its proper divisors (1).

78294247309 is an equidigital number, since it uses as much as digits as its factorization.

78294247309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6096384, while the sum is 55.

The spelling of 78294247309 in words is "seventy-eight billion, two hundred ninety-four million, two hundred forty-seven thousand, three hundred nine".