394021 has 4 divisors (see below), whose sum is σ = 395500. Its totient is φ = 392544.

The previous prime is 394019. The next prime is 394039. The reversal of 394021 is 120493.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120493 = 101 ⋅1193.

It can be written as a sum of positive squares in 2 ways, for example, as 148996 + 245025 = 386^2 + 495^2 .

It is a cyclic number.

It is not a de Polignac number, because 394021 - 2¹ = 394019 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 394021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (394721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 216 + ... + 913.

It is an arithmetic number, because the mean of its divisors is an integer number (98875).

2³⁹⁴⁰²¹ is an apocalyptic number.

It is an amenable number.

394021 is a deficient number, since it is larger than the sum of its proper divisors (1479).

394021 is a wasteful number, since it uses less digits than its factorization.

394021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1478.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 394021 is about 627.7109207270. The cubic root of 394021 is about 73.3116717472.

The spelling of 394021 in words is "three hundred ninety-four thousand, twenty-one".