68211809 has 2 divisors, whose sum is σ = 68211810. Its totient is φ = 68211808.

The previous prime is 68211761. The next prime is 68211883. The reversal of 68211809 is 90811286.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35664784 + 32547025 = 5972^2 + 5705^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68211809 is a prime.

It is not a weakly prime, because it can be changed into another prime (68210809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34105904 + 34105905.

It is an arithmetic number, because the mean of its divisors is an integer number (34105905).

Almost surely, 2^68211809 is an apocalyptic number.

It is an amenable number.

68211809 is a deficient number, since it is larger than the sum of its proper divisors (1).

68211809 is an equidigital number, since it uses as much as digits as its factorization.

68211809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 68211809 is about 8259.0440730147. The cubic root of 68211809 is about 408.5888607851.

The spelling of 68211809 in words is "sixty-eight million, two hundred eleven thousand, eight hundred nine".