68244721 has 2 divisors, whose sum is σ = 68244722. Its totient is φ = 68244720.

The previous prime is 68244679. The next prime is 68244739. The reversal of 68244721 is 12744286.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35343025 + 32901696 = 5945^2 + 5736^2 .

It is a cyclic number.

It is not a de Polignac number, because 68244721 - 2¹¹ = 68242673 is a prime.

It is not a weakly prime, because it can be changed into another prime (68244821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34122360 + 34122361.

It is an arithmetic number, because the mean of its divisors is an integer number (34122361).

Almost surely, 2^68244721 is an apocalyptic number.

It is an amenable number.

68244721 is a deficient number, since it is larger than the sum of its proper divisors (1).

68244721 is an equidigital number, since it uses as much as digits as its factorization.

68244721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21504, while the sum is 34.

The square root of 68244721 is about 8261.0363151363. The cubic root of 68244721 is about 408.6545645324.

The spelling of 68244721 in words is "sixty-eight million, two hundred forty-four thousand, seven hundred twenty-one".