78833917649 has 2 divisors, whose sum is σ = 78833917650. Its totient is φ = 78833917648.

The previous prime is 78833917619. The next prime is 78833917667. The reversal of 78833917649 is 94671933887.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68885251600 + 9948666049 = 262460^2 + 99743^2 .

It is an emirp because it is prime and its reverse (94671933887) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78833917649 - 2¹⁶ = 78833852113 is a prime.

It is not a weakly prime, because it can be changed into another prime (78833917609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39416958824 + 39416958825.

It is an arithmetic number, because the mean of its divisors is an integer number (39416958825).

Almost surely, 2^78833917649 is an apocalyptic number.

It is an amenable number.

78833917649 is a deficient number, since it is larger than the sum of its proper divisors (1).

78833917649 is an equidigital number, since it uses as much as digits as its factorization.

78833917649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54867456, while the sum is 65.

The spelling of 78833917649 in words is "seventy-eight billion, eight hundred thirty-three million, nine hundred seventeen thousand, six hundred forty-nine".