78765173939 has 2 divisors, whose sum is σ = 78765173940. Its totient is φ = 78765173938.

The previous prime is 78765173849. The next prime is 78765173941. The reversal of 78765173939 is 93937156787.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78765173939 - 2¹² = 78765169843 is a prime.

Together with 78765173941, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78765173339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39382586969 + 39382586970.

It is an arithmetic number, because the mean of its divisors is an integer number (39382586970).

Almost surely, 2^78765173939 is an apocalyptic number.

78765173939 is a deficient number, since it is larger than the sum of its proper divisors (1).

78765173939 is an equidigital number, since it uses as much as digits as its factorization.

78765173939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60011280, while the sum is 65.

It can be divided in two parts, 7876 and 5173939, that added together give a palindrome (5181815).

The spelling of 78765173939 in words is "seventy-eight billion, seven hundred sixty-five million, one hundred seventy-three thousand, nine hundred thirty-nine".