394906905 has 12 divisors (see below), whose sum is σ = 684505380. Its totient is φ = 210616992.

The previous prime is 394906903. The next prime is 394906913. The reversal of 394906905 is 509609493.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 47941776 + 346965129 = 6924^2 + 18627^2 .

It is not a de Polignac number, because 394906905 - 2¹ = 394906903 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 8775709 = 394906905 / (3 + 9 + 4 + 9 + 0 + 6 + 9 + 0 + 5).

It is not an unprimeable number, because it can be changed into a prime (394906903) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4387810 + ... + 4387899.

It is an arithmetic number, because the mean of its divisors is an integer number (57042115).

Almost surely, 2^394906905 is an apocalyptic number.

It is an amenable number.

394906905 is a deficient number, since it is larger than the sum of its proper divisors (289598475).

394906905 is a wasteful number, since it uses less digits than its factorization.

394906905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8775720 (or 8775717 counting only the distinct ones).

The product of its (nonzero) digits is 262440, while the sum is 45.

The square root of 394906905 is about 19872.2647174397. The cubic root of 394906905 is about 733.6657454187.

The spelling of 394906905 in words is "three hundred ninety-four million, nine hundred six thousand, nine hundred five".