395972309 has 2 divisors, whose sum is σ = 395972310. Its totient is φ = 395972308.

The previous prime is 395972299. The next prime is 395972327. The reversal of 395972309 is 903279593.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 244140625 + 151831684 = 15625^2 + 12322^2 .

It is an emirp because it is prime and its reverse (903279593) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 395972309 - 2¹² = 395968213 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (395972009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197986154 + 197986155.

It is an arithmetic number, because the mean of its divisors is an integer number (197986155).

Almost surely, 2^395972309 is an apocalyptic number.

It is an amenable number.

395972309 is a deficient number, since it is larger than the sum of its proper divisors (1).

395972309 is an equidigital number, since it uses as much as digits as its factorization.

395972309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 459270, while the sum is 47.

The square root of 395972309 is about 19899.0529674153. The cubic root of 395972309 is about 734.3249290841.

The spelling of 395972309 in words is "three hundred ninety-five million, nine hundred seventy-two thousand, three hundred nine".