3851921 has 4 divisors (see below), whose sum is σ = 3857700. Its totient is φ = 3846144.

The previous prime is 3851917. The next prime is 3851923. The reversal of 3851921 is 1291583.

3851921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1291583 = 311 ⋅4153.

It can be written as a sum of positive squares in 2 ways, for example, as 1661521 + 2190400 = 1289^2 + 1480^2 .

It is a cyclic number.

It is not a de Polignac number, because 3851921 - 2² = 3851917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3851923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1736 + ... + 3273.

It is an arithmetic number, because the mean of its divisors is an integer number (964425).

Almost surely, 2^3851921 is an apocalyptic number.

It is an amenable number.

3851921 is a deficient number, since it is larger than the sum of its proper divisors (5779).

3851921 is an equidigital number, since it uses as much as digits as its factorization.

3851921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5778.

The product of its digits is 2160, while the sum is 29.

The square root of 3851921 is about 1962.6311421151. The cubic root of 3851921 is about 156.7565838642.

The spelling of 3851921 in words is "three million, eight hundred fifty-one thousand, nine hundred twenty-one".