68145821 has 2 divisors, whose sum is σ = 68145822. Its totient is φ = 68145820.

The previous prime is 68145797. The next prime is 68145829. The reversal of 68145821 is 12854186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50623225 + 17522596 = 7115^2 + 4186^2 .

It is a cyclic number.

It is not a de Polignac number, because 68145821 - 2¹⁴ = 68129437 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68145829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34072910 + 34072911.

It is an arithmetic number, because the mean of its divisors is an integer number (34072911).

Almost surely, 2^68145821 is an apocalyptic number.

It is an amenable number.

68145821 is a deficient number, since it is larger than the sum of its proper divisors (1).

68145821 is an equidigital number, since it uses as much as digits as its factorization.

68145821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15360, while the sum is 35.

The square root of 68145821 is about 8255.0482130633. The cubic root of 68145821 is about 408.4570621951.

The spelling of 68145821 in words is "sixty-eight million, one hundred forty-five thousand, eight hundred twenty-one".