3941821 has 4 divisors (see below), whose sum is σ = 4245052. Its totient is φ = 3638592.

The previous prime is 3941803. The next prime is 3941831. The reversal of 3941821 is 1281493.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1281493 = 19 ⋅67447.

It can be written as a sum of positive squares in 2 ways, for example, as 1413721 + 2528100 = 1189^2 + 1590^2 .

It is a cyclic number.

It is not a de Polignac number, because 3941821 - 2¹¹ = 3939773 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 3941821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3941801) 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 3 ways as a sum of consecutive naturals, for example, 151596 + ... + 151621.

It is an arithmetic number, because the mean of its divisors is an integer number (1061263).

Almost surely, 2^3941821 is an apocalyptic number.

It is an amenable number.

3941821 is a deficient number, since it is larger than the sum of its proper divisors (303231).

3941821 is a wasteful number, since it uses less digits than its factorization.

3941821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303230.

The product of its digits is 1728, while the sum is 28.

The square root of 3941821 is about 1985.4019744122. The cubic root of 3941821 is about 157.9667317661.

The spelling of 3941821 in words is "three million, nine hundred forty-one thousand, eight hundred twenty-one".