68965009721 has 2 divisors, whose sum is σ = 68965009722. Its totient is φ = 68965009720.

The previous prime is 68965009691. The next prime is 68965009739. The reversal of 68965009721 is 12790056986.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56323155625 + 12641854096 = 237325^2 + 112436^2 .

It is a cyclic number.

It is not a de Polignac number, because 68965009721 - 2¹⁴ = 68964993337 is a prime.

It is not a weakly prime, because it can be changed into another prime (68965009741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34482504860 + 34482504861.

It is an arithmetic number, because the mean of its divisors is an integer number (34482504861).

Almost surely, 2^68965009721 is an apocalyptic number.

It is an amenable number.

68965009721 is a deficient number, since it is larger than the sum of its proper divisors (1).

68965009721 is an equidigital number, since it uses as much as digits as its factorization.

68965009721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1632960, while the sum is 53.

The spelling of 68965009721 in words is "sixty-eight billion, nine hundred sixty-five million, nine thousand, seven hundred twenty-one".