309000073 has 2 divisors, whose sum is σ = 309000074. Its totient is φ = 309000072.

The previous prime is 309000071. The next prime is 309000077. The reversal of 309000073 is 370000903.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 308072704 + 927369 = 17552^2 + 963^2 .

It is a cyclic number.

It is not a de Polignac number, because 309000073 - 2¹ = 309000071 is a prime.

It is a super-2 number, since 2×309000073² = 190962090228010658, which contains 22 as substring.

Together with 309000071, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (309000071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154500036 + 154500037.

It is an arithmetic number, because the mean of its divisors is an integer number (154500037).

Almost surely, 2^309000073 is an apocalyptic number.

It is an amenable number.

309000073 is a deficient number, since it is larger than the sum of its proper divisors (1).

309000073 is an equidigital number, since it uses as much as digits as its factorization.

309000073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 567, while the sum is 22.

The square root of 309000073 is about 17578.3979076593. The cubic root of 309000073 is about 676.0614834138.

Adding to 309000073 its reverse (370000903), we get a palindrome (679000976).

The spelling of 309000073 in words is "three hundred nine million, seventy-three", and thus it is an aban number.