3938386221 has 36 divisors (see below), whose sum is σ = 7219165824. Its totient is φ = 2045912400.

The previous prime is 3938386201. The next prime is 3938386237. The reversal of 3938386221 is 1226838393.

3938386221 is a `hidden beast` number, since 393 + 8 + 38 + 6 + 221 = 666.

It is not a de Polignac number, because 3938386221 - 2⁵ = 3938386189 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3938386201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 401085 + ... + 410786.

It is an arithmetic number, because the mean of its divisors is an integer number (200532384).

Almost surely, 2^3938386221 is an apocalyptic number.

It is an amenable number.

3938386221 is a deficient number, since it is larger than the sum of its proper divisors (3280779603).

3938386221 is a wasteful number, since it uses less digits than its factorization.

3938386221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 811902 (or 811892 counting only the distinct ones).

The product of its digits is 373248, while the sum is 45.

The square root of 3938386221 is about 62756.5631707155. The cubic root of 3938386221 is about 1579.2083601678.

The spelling of 3938386221 in words is "three billion, nine hundred thirty-eight million, three hundred eighty-six thousand, two hundred twenty-one".