68481132721 has 9 divisors (see below), whose sum is σ = 68937648249. Its totient is φ = 68027625684.

The previous prime is 68481132703. The next prime is 68481132737. The reversal of 68481132721 is 12723118486.

The square root of 68481132721 is 261689.

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

It is not a de Polignac number, because 68481132721 - 2¹¹ = 68481130673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68481132791) 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, 43701280 + ... + 43702846.

Almost surely, 2^68481132721 is an apocalyptic number.

68481132721 is the 261689-th square number.

68481132721 is the 130845-th centered octagonal number.

It is an amenable number.

68481132721 is a deficient number, since it is larger than the sum of its proper divisors (456515528).

68481132721 is an frugal number, since it uses more digits than its factorization.

68481132721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3468 (or 1734 counting only the distinct ones).

The product of its digits is 129024, while the sum is 43.

The spelling of 68481132721 in words is "sixty-eight billion, four hundred eighty-one million, one hundred thirty-two thousand, seven hundred twenty-one".