68649979481 has 2 divisors, whose sum is σ = 68649979482. Its totient is φ = 68649979480.

The previous prime is 68649979469. The next prime is 68649979529. The reversal of 68649979481 is 18497994686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67166497225 + 1483482256 = 259165^2 + 38516^2 .

It is a cyclic number.

It is not a de Polignac number, because 68649979481 - 2⁶ = 68649979417 is a prime.

It is a super-2 number, since 2×68649979481² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (68649979781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34324989740 + 34324989741.

It is an arithmetic number, because the mean of its divisors is an integer number (34324989741).

Almost surely, 2^68649979481 is an apocalyptic number.

It is an amenable number.

68649979481 is a deficient number, since it is larger than the sum of its proper divisors (1).

68649979481 is an equidigital number, since it uses as much as digits as its factorization.

68649979481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 188116992, while the sum is 71.

The spelling of 68649979481 in words is "sixty-eight billion, six hundred forty-nine million, nine hundred seventy-nine thousand, four hundred eighty-one".