394447905 has 24 divisors (see below), whose sum is σ = 684980712. Its totient is φ = 209981184.

The previous prime is 394447897. The next prime is 394447909. The reversal of 394447905 is 509744493.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 39050001 + 355397904 = 6249^2 + 18852^2 .

It is not a de Polignac number, because 394447905 - 2³ = 394447897 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (394447909) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17197 + ... + 32933.

It is an arithmetic number, because the mean of its divisors is an integer number (28540863).

Almost surely, 2^394447905 is an apocalyptic number.

It is an amenable number.

394447905 is a deficient number, since it is larger than the sum of its proper divisors (290532807).

394447905 is a wasteful number, since it uses less digits than its factorization.

394447905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16305 (or 16302 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The square root of 394447905 is about 19860.7126005086. The cubic root of 394447905 is about 733.3813888389.

The spelling of 394447905 in words is "three hundred ninety-four million, four hundred forty-seven thousand, nine hundred five".