78041278309 has 2 divisors, whose sum is σ = 78041278310. Its totient is φ = 78041278308.

The previous prime is 78041278261. The next prime is 78041278339. The reversal of 78041278309 is 90387214087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57493489284 + 20547789025 = 239778^2 + 143345^2 .

It is a cyclic number.

It is not a de Polignac number, because 78041278309 - 2¹⁷ = 78041147237 is a prime.

It is a super-2 number, since 2×78041278309² (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 (78041278339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39020639154 + 39020639155.

It is an arithmetic number, because the mean of its divisors is an integer number (39020639155).

Almost surely, 2^78041278309 is an apocalyptic number.

It is an amenable number.

78041278309 is a deficient number, since it is larger than the sum of its proper divisors (1).

78041278309 is an equidigital number, since it uses as much as digits as its factorization.

78041278309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 677376, while the sum is 49.

The spelling of 78041278309 in words is "seventy-eight billion, forty-one million, two hundred seventy-eight thousand, three hundred nine".