78745623841 has 2 divisors, whose sum is σ = 78745623842. Its totient is φ = 78745623840.

The previous prime is 78745623821. The next prime is 78745623907. The reversal of 78745623841 is 14832654787.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74036233216 + 4709390625 = 272096^2 + 68625^2 .

It is an emirp because it is prime and its reverse (14832654787) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78745623841 - 2¹⁹ = 78745099553 is a prime.

It is not a weakly prime, because it can be changed into another prime (78745623821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39372811920 + 39372811921.

It is an arithmetic number, because the mean of its divisors is an integer number (39372811921).

Almost surely, 2^78745623841 is an apocalyptic number.

It is an amenable number.

78745623841 is a deficient number, since it is larger than the sum of its proper divisors (1).

78745623841 is an equidigital number, since it uses as much as digits as its factorization.

78745623841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9031680, while the sum is 55.

The spelling of 78745623841 in words is "seventy-eight billion, seven hundred forty-five million, six hundred twenty-three thousand, eight hundred forty-one".