3938221 has 16 divisors (see below), whose sum is σ = 4785408. Its totient is φ = 3168000.

The previous prime is 3938197. The next prime is 3938251. The reversal of 3938221 is 1228393.

3938221 is a nontrivial binomial coefficient, being equal to C(2807, 2).

It is a 4-Lehmer number, since φ(3938221) divides (3938221-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 3938221 - 2⁹ = 3937709 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 3938221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3938251) 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, 9621 + ... + 10021.

It is an arithmetic number, because the mean of its divisors is an integer number (299088).

Almost surely, 2^3938221 is an apocalyptic number.

3938221 is the 2806-th triangular number.

3938221 is the 936-th centered nonagonal number.

It is an amenable number.

3938221 is a deficient number, since it is larger than the sum of its proper divisors (847187).

3938221 is a wasteful number, since it uses less digits than its factorization.

3938221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 492.

The product of its digits is 2592, while the sum is 28.

The square root of 3938221 is about 1984.4951499059. The cubic root of 3938221 is about 157.9186276500.

The spelling of 3938221 in words is "three million, nine hundred thirty-eight thousand, two hundred twenty-one".