394985309 has 8 divisors (see below), whose sum is σ = 409038552. Its totient is φ = 381176640.

The previous prime is 394985273. The next prime is 394985317. The reversal of 394985309 is 903589493.

It can be written as a sum of positive squares in 4 ways, for example, as 83356900 + 311628409 = 9130^2 + 17653^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 394985309 - 2²⁴ = 378208093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (394985369) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57854 + ... + 64319.

It is an arithmetic number, because the mean of its divisors is an integer number (51129819).

Almost surely, 2^394985309 is an apocalyptic number.

It is an amenable number.

394985309 is a deficient number, since it is larger than the sum of its proper divisors (14053243).

394985309 is a wasteful number, since it uses less digits than its factorization.

394985309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122287.

The product of its (nonzero) digits is 1049760, while the sum is 50.

The square root of 394985309 is about 19874.2373186998. The cubic root of 394985309 is about 733.7142956990.

The spelling of 394985309 in words is "three hundred ninety-four million, nine hundred eighty-five thousand, three hundred nine".