394213609 has 4 divisors (see below), whose sum is σ = 394256016. Its totient is φ = 394171204.

The previous prime is 394213597. The next prime is 394213619. The reversal of 394213609 is 906312493.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 906312493 = 23 ⋅39404891.

It is a cyclic number.

It is not a de Polignac number, because 394213609 - 2¹³ = 394205417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (394213619) 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 in 3 ways as a sum of consecutive naturals, for example, 559 + ... + 28084.

It is an arithmetic number, because the mean of its divisors is an integer number (98564004).

Almost surely, 2^394213609 is an apocalyptic number.

It is an amenable number.

394213609 is a deficient number, since it is larger than the sum of its proper divisors (42407).

394213609 is a wasteful number, since it uses less digits than its factorization.

394213609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42406.

The product of its (nonzero) digits is 34992, while the sum is 37.

The square root of 394213609 is about 19854.8132451554. The cubic root of 394213609 is about 733.2361543174.

The spelling of 394213609 in words is "three hundred ninety-four million, two hundred thirteen thousand, six hundred nine".