78378622717 has 2 divisors, whose sum is σ = 78378622718. Its totient is φ = 78378622716.

The previous prime is 78378622709. The next prime is 78378622793. The reversal of 78378622717 is 71722687387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44397018436 + 33981604281 = 210706^2 + 184341^2 .

It is a cyclic number.

It is not a de Polignac number, because 78378622717 - 2³ = 78378622709 is a prime.

It is a super-2 number, since 2×78378622717² (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 (78378629717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39189311358 + 39189311359.

It is an arithmetic number, because the mean of its divisors is an integer number (39189311359).

Almost surely, 2^78378622717 is an apocalyptic number.

It is an amenable number.

78378622717 is a deficient number, since it is larger than the sum of its proper divisors (1).

78378622717 is an equidigital number, since it uses as much as digits as its factorization.

78378622717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11063808, while the sum is 58.

The spelling of 78378622717 in words is "seventy-eight billion, three hundred seventy-eight million, six hundred twenty-two thousand, seven hundred seventeen".