68813036521 has 4 divisors (see below), whose sum is σ = 68910093700. Its totient is φ = 68715979344.

The previous prime is 68813036429. The next prime is 68813036533. The reversal of 68813036521 is 12563031886.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12563031886 = 2 ⋅6281515943.

It can be written as a sum of positive squares in 2 ways, for example, as 27311198121 + 41501838400 = 165261^2 + 203720^2 .

It is a cyclic number.

It is not a de Polignac number, because 68813036521 - 2⁷ = 68813036393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68813036021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48527526 + ... + 48528943.

It is an arithmetic number, because the mean of its divisors is an integer number (17227523425).

Almost surely, 2^68813036521 is an apocalyptic number.

It is an amenable number.

68813036521 is a deficient number, since it is larger than the sum of its proper divisors (97057179).

68813036521 is an equidigital number, since it uses as much as digits as its factorization.

68813036521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97057178.

The product of its (nonzero) digits is 207360, while the sum is 43.

The spelling of 68813036521 in words is "sixty-eight billion, eight hundred thirteen million, thirty-six thousand, five hundred twenty-one".