309516397 has 2 divisors, whose sum is σ = 309516398. Its totient is φ = 309516396.

The previous prime is 309516377. The next prime is 309516413. The reversal of 309516397 is 793615903.

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., 309267396 + 249001 = 17586^2 + 499^2 .

It is a cyclic number.

It is not a de Polignac number, because 309516397 - 2¹¹ = 309514349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (309516367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154758198 + 154758199.

It is an arithmetic number, because the mean of its divisors is an integer number (154758199).

Almost surely, 2^309516397 is an apocalyptic number.

It is an amenable number.

309516397 is a deficient number, since it is larger than the sum of its proper divisors (1).

309516397 is an equidigital number, since it uses as much as digits as its factorization.

309516397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 153090, while the sum is 43.

The square root of 309516397 is about 17593.0780990707. The cubic root of 309516397 is about 676.4378290910.

The spelling of 309516397 in words is "three hundred nine million, five hundred sixteen thousand, three hundred ninety-seven".