394121609 has 4 divisors (see below), whose sum is σ = 450424704. Its totient is φ = 337818516.

The previous prime is 394121603. The next prime is 394121641. The reversal of 394121609 is 906121493.

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.

It is a de Polignac number, because none of the positive numbers 2^k-394121609 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (394121603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28151537 + ... + 28151550.

It is an arithmetic number, because the mean of its divisors is an integer number (112606176).

Almost surely, 2^394121609 is an apocalyptic number.

It is an amenable number.

394121609 is a deficient number, since it is larger than the sum of its proper divisors (56303095).

394121609 is an equidigital number, since it uses as much as digits as its factorization.

394121609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56303094.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 394121609 is about 19852.4962913987. The cubic root of 394121609 is about 733.1791099697.

The spelling of 394121609 in words is "three hundred ninety-four million, one hundred twenty-one thousand, six hundred nine".