79748640217 has 2 divisors, whose sum is σ = 79748640218. Its totient is φ = 79748640216.

The previous prime is 79748640157. The next prime is 79748640221. The reversal of 79748640217 is 71204684797.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69006561481 + 10742078736 = 262691^2 + 103644^2 .

It is an emirp because it is prime and its reverse (71204684797) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79748640217 is a prime.

It is not a weakly prime, because it can be changed into another prime (79748670217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39874320108 + 39874320109.

It is an arithmetic number, because the mean of its divisors is an integer number (39874320109).

Almost surely, 2^79748640217 is an apocalyptic number.

It is an amenable number.

79748640217 is a deficient number, since it is larger than the sum of its proper divisors (1).

79748640217 is an equidigital number, since it uses as much as digits as its factorization.

79748640217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4741632, while the sum is 55.

The spelling of 79748640217 in words is "seventy-nine billion, seven hundred forty-eight million, six hundred forty thousand, two hundred seventeen".