3994921 has 16 divisors (see below), whose sum is σ = 4912000. Its totient is φ = 3238704.

The previous prime is 3994909. The next prime is 3994931. The reversal of 3994921 is 1294993.

It is not a de Polignac number, because 3994921 - 2¹¹ = 3992873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3994931) 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 15 ways as a sum of consecutive naturals, for example, 6211 + ... + 6823.

It is an arithmetic number, because the mean of its divisors is an integer number (307000).

Almost surely, 2^3994921 is an apocalyptic number.

It is an amenable number.

3994921 is a deficient number, since it is larger than the sum of its proper divisors (917079).

3994921 is an equidigital number, since it uses as much as digits as its factorization.

3994921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 653 (or 639 counting only the distinct ones).

The product of its digits is 17496, while the sum is 37.

The square root of 3994921 is about 1998.7298466776. The cubic root of 3994921 is about 158.6728899904.

The spelling of 3994921 in words is "three million, nine hundred ninety-four thousand, nine hundred twenty-one".