73281209 has 2 divisors, whose sum is σ = 73281210. Its totient is φ = 73281208.

The previous prime is 73281167. The next prime is 73281223. The reversal of 73281209 is 90218237.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55875625 + 17405584 = 7475^2 + 4172^2 .

It is a cyclic number.

It is not a de Polignac number, because 73281209 - 2¹⁶ = 73215673 is a prime.

It is a Chen prime.

It is equal to p_4299530 and since 73281209 and 4299530 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (73281809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36640604 + 36640605.

It is an arithmetic number, because the mean of its divisors is an integer number (36640605).

Almost surely, 2^73281209 is an apocalyptic number.

It is an amenable number.

73281209 is a deficient number, since it is larger than the sum of its proper divisors (1).

73281209 is an equidigital number, since it uses as much as digits as its factorization.

73281209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 73281209 is about 8560.4444393968. Note that the first 4 decimals coincide. The cubic root of 73281209 is about 418.4698839778.

The spelling of 73281209 in words is "seventy-three million, two hundred eighty-one thousand, two hundred nine".