394057309 has 2 divisors, whose sum is σ = 394057310. Its totient is φ = 394057308.

The previous prime is 394057303. The next prime is 394057369. The reversal of 394057309 is 903750493.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 233325625 + 160731684 = 15275^2 + 12678^2 .

It is a cyclic number.

It is not a de Polignac number, because 394057309 - 2⁵ = 394057277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (394057303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197028654 + 197028655.

It is an arithmetic number, because the mean of its divisors is an integer number (197028655).

Almost surely, 2^394057309 is an apocalyptic number.

It is an amenable number.

394057309 is a deficient number, since it is larger than the sum of its proper divisors (1).

394057309 is an equidigital number, since it uses as much as digits as its factorization.

394057309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 102060, while the sum is 40.

The square root of 394057309 is about 19850.8767816437. The cubic root of 394057309 is about 733.1392356604.

The spelling of 394057309 in words is "three hundred ninety-four million, fifty-seven thousand, three hundred nine".