3878021 has 4 divisors (see below), whose sum is σ = 4432032. Its totient is φ = 3324012.

The previous prime is 3878003. The next prime is 3878051. The reversal of 3878021 is 1208783.

3878021 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 a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1208783 = 31 ⋅38993.

It is a cyclic number.

It is not a de Polignac number, because 3878021 - 2¹⁰ = 3876997 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3878051) 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, 276995 + ... + 277008.

It is an arithmetic number, because the mean of its divisors is an integer number (1108008).

Almost surely, 2^3878021 is an apocalyptic number.

It is an amenable number.

3878021 is a deficient number, since it is larger than the sum of its proper divisors (554011).

3878021 is an equidigital number, since it uses as much as digits as its factorization.

3878021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554010.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 3878021 is about 1969.2691537725. The cubic root of 3878021 is about 157.1098396983.

The spelling of 3878021 in words is "three million, eight hundred seventy-eight thousand, twenty-one".