3864821 has 2 divisors, whose sum is σ = 3864822. Its totient is φ = 3864820.

The previous prime is 3864811. The next prime is 3864827. The reversal of 3864821 is 1284683.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3783025 + 81796 = 1945^2 + 286^2 .

It is a cyclic number.

It is not a de Polignac number, because 3864821 - 2¹⁴ = 3848437 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3864827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1932410 + 1932411.

It is an arithmetic number, because the mean of its divisors is an integer number (1932411).

Almost surely, 2^3864821 is an apocalyptic number.

It is an amenable number.

3864821 is a deficient number, since it is larger than the sum of its proper divisors (1).

3864821 is an equidigital number, since it uses as much as digits as its factorization.

3864821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9216, while the sum is 32.

The square root of 3864821 is about 1965.9147997815. The cubic root of 3864821 is about 156.9313803474.

The spelling of 3864821 in words is "three million, eight hundred sixty-four thousand, eight hundred twenty-one".