309905069 has 2 divisors, whose sum is σ = 309905070. Its totient is φ = 309905068.

The previous prime is 309905051. The next prime is 309905077. The reversal of 309905069 is 960509903.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 241429444 + 68475625 = 15538^2 + 8275^2 .

It is a cyclic number.

It is not a de Polignac number, because 309905069 - 2⁸ = 309904813 is a prime.

It is a super-2 number, since 2×309905069² = 192082303583789522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (309905569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154952534 + 154952535.

It is an arithmetic number, because the mean of its divisors is an integer number (154952535).

Almost surely, 2^309905069 is an apocalyptic number.

It is an amenable number.

309905069 is a deficient number, since it is larger than the sum of its proper divisors (1).

309905069 is an equidigital number, since it uses as much as digits as its factorization.

309905069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 65610, while the sum is 41.

The square root of 309905069 is about 17604.1207959955. The cubic root of 309905069 is about 676.7208539143.

It can be divided in two parts, 30 and 9905069, that added together give a palindrome (9905099).

The spelling of 309905069 in words is "three hundred nine million, nine hundred five thousand, sixty-nine".