394004721 has 16 divisors (see below), whose sum is σ = 574979328. Its totient is φ = 238006800.

The previous prime is 394004717. The next prime is 394004747. The reversal of 394004721 is 127400493.

It is a happy number.

It is not a de Polignac number, because 394004721 - 2² = 394004717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (394004321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9315 + ... + 29576.

It is an arithmetic number, because the mean of its divisors is an integer number (35936208).

Almost surely, 2^394004721 is an apocalyptic number.

It is an amenable number.

394004721 is a deficient number, since it is larger than the sum of its proper divisors (180974607).

394004721 is a wasteful number, since it uses less digits than its factorization.

394004721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39212.

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 394004721 is about 19849.5521611950. The cubic root of 394004721 is about 733.1066210800.

The spelling of 394004721 in words is "three hundred ninety-four million, four thousand, seven hundred twenty-one".