3801821 has 4 divisors (see below), whose sum is σ = 3807132. Its totient is φ = 3796512.

The previous prime is 3801803. The next prime is 3801827. The reversal of 3801821 is 1281083.

3801821 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.

It can be written as a sum of positive squares in 2 ways, for example, as 1276900 + 2524921 = 1130^2 + 1589^2 .

It is a cyclic number.

It is not a de Polignac number, because 3801821 - 2⁶ = 3801757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3801827) 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, 1376 + ... + 3081.

It is an arithmetic number, because the mean of its divisors is an integer number (951783).

Almost surely, 2^3801821 is an apocalyptic number.

It is an amenable number.

3801821 is a deficient number, since it is larger than the sum of its proper divisors (5311).

3801821 is an equidigital number, since it uses as much as digits as its factorization.

3801821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5310.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 3801821 is about 1949.8258896630. The cubic root of 3801821 is about 156.0739978766.

The spelling of 3801821 in words is "three million, eight hundred one thousand, eight hundred twenty-one".