67136809 has 2 divisors, whose sum is σ = 67136810. Its totient is φ = 67136808.

The previous prime is 67136777. The next prime is 67136831. The reversal of 67136809 is 90863176.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60886809 + 6250000 = 7803^2 + 2500^2 .

It is a cyclic number.

It is not a de Polignac number, because 67136809 - 2⁵ = 67136777 is a prime.

It is a super-2 number, since 2×67136809² = 9014702245404962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (67130809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33568404 + 33568405.

It is an arithmetic number, because the mean of its divisors is an integer number (33568405).

Almost surely, 2^67136809 is an apocalyptic number.

It is an amenable number.

67136809 is a deficient number, since it is larger than the sum of its proper divisors (1).

67136809 is an equidigital number, since it uses as much as digits as its factorization.

67136809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 67136809 is about 8193.7054499170. The cubic root of 67136809 is about 406.4310680344.

The spelling of 67136809 in words is "sixty-seven million, one hundred thirty-six thousand, eight hundred nine".