68849518548721 has 9 divisors (see below), whose sum is σ = 68898085211361. Its totient is φ = 68800986114432.

The previous prime is 68849518548689. The next prime is 68849518548737. The reversal of 68849518548721 is 12784581594886.

The square root of 68849518548721 is 8297561.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 13029493710321 + 55820024838400 = 3609639^2 + 7471280^2 .

It is not a de Polignac number, because 68849518548721 - 2⁵ = 68849518548689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68849518518721) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 20055203221 + ... + 20055206653.

Almost surely, 2^{68849518548721} is an apocalyptic number.

68849518548721 is the 8297561-st square number.

68849518548721 is the 4148781-st centered octagonal number.

It is an amenable number.

68849518548721 is a deficient number, since it is larger than the sum of its proper divisors (48566662640).

68849518548721 is an frugal number, since it uses more digits than its factorization.

68849518548721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11700 (or 5850 counting only the distinct ones).

The product of its digits is 1238630400, while the sum is 76.

The spelling of 68849518548721 in words is "sixty-eight trillion, eight hundred forty-nine billion, five hundred eighteen million, five hundred forty-eight thousand, seven hundred twenty-one".