68631209 has 2 divisors, whose sum is σ = 68631210. Its totient is φ = 68631208.

The previous prime is 68631203. The next prime is 68631221. The reversal of 68631209 is 90213686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67699984 + 931225 = 8228^2 + 965^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68631209 is a prime.

It is not a weakly prime, because it can be changed into another prime (68631203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34315604 + 34315605.

It is an arithmetic number, because the mean of its divisors is an integer number (34315605).

Almost surely, 2^68631209 is an apocalyptic number.

It is an amenable number.

68631209 is a deficient number, since it is larger than the sum of its proper divisors (1).

68631209 is an equidigital number, since it uses as much as digits as its factorization.

68631209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 68631209 is about 8284.3955120455. The cubic root of 68631209 is about 409.4245526249.

The spelling of 68631209 in words is "sixty-eight million, six hundred thirty-one thousand, two hundred nine".