394663505 has 4 divisors (see below), whose sum is σ = 473596212. Its totient is φ = 315730800.

The previous prime is 394663501. The next prime is 394663513. The reversal of 394663505 is 505366493.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 505366493 = 643 ⋅785951.

It can be written as a sum of positive squares in 2 ways, for example, as 74718736 + 319944769 = 8644^2 + 17887^2 .

It is not a de Polignac number, because 394663505 - 2² = 394663501 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (394663501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39466346 + ... + 39466355.

It is an arithmetic number, because the mean of its divisors is an integer number (118399053).

Almost surely, 2^394663505 is an apocalyptic number.

It is an amenable number.

394663505 is a deficient number, since it is larger than the sum of its proper divisors (78932707).

394663505 is an equidigital number, since it uses as much as digits as its factorization.

394663505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78932706.

The product of its (nonzero) digits is 291600, while the sum is 41.

The square root of 394663505 is about 19866.1396602360. The cubic root of 394663505 is about 733.5149833524.

The spelling of 394663505 in words is "three hundred ninety-four million, six hundred sixty-three thousand, five hundred five".