78143967509 has 2 divisors, whose sum is σ = 78143967510. Its totient is φ = 78143967508.

The previous prime is 78143967481. The next prime is 78143967511. The reversal of 78143967509 is 90576934187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54396232900 + 23747734609 = 233230^2 + 154103^2 .

It is a cyclic number.

It is not a de Polignac number, because 78143967509 - 2¹⁶ = 78143901973 is a prime.

It is a super-2 number, since 2×78143967509² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 78143967511, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78143967709) 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, 39071983754 + 39071983755.

It is an arithmetic number, because the mean of its divisors is an integer number (39071983755).

Almost surely, 2^78143967509 is an apocalyptic number.

It is an amenable number.

78143967509 is a deficient number, since it is larger than the sum of its proper divisors (1).

78143967509 is an equidigital number, since it uses as much as digits as its factorization.

78143967509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11430720, while the sum is 59.

The spelling of 78143967509 in words is "seventy-eight billion, one hundred forty-three million, nine hundred sixty-seven thousand, five hundred nine".