309231073 has 2 divisors, whose sum is σ = 309231074. Its totient is φ = 309231072.

The previous prime is 309231011. The next prime is 309231121. The reversal of 309231073 is 370132903.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 257506209 + 51724864 = 16047^2 + 7192^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-309231073 is a prime.

It is not a weakly prime, because it can be changed into another prime (309232073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154615536 + 154615537.

It is an arithmetic number, because the mean of its divisors is an integer number (154615537).

Almost surely, 2^309231073 is an apocalyptic number.

It is an amenable number.

309231073 is a deficient number, since it is larger than the sum of its proper divisors (1).

309231073 is an equidigital number, since it uses as much as digits as its factorization.

309231073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3402, while the sum is 28.

The square root of 309231073 is about 17584.9672447804. The cubic root of 309231073 is about 676.2299098062.

Adding to 309231073 its reverse (370132903), we get a palindrome (679363976).

The spelling of 309231073 in words is "three hundred nine million, two hundred thirty-one thousand, seventy-three".