3821921 has 4 divisors (see below), whose sum is σ = 3828144. Its totient is φ = 3815700.

The previous prime is 3821911. The next prime is 3821929. The reversal of 3821921 is 1291283.

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.

It is a cyclic number.

It is not a de Polignac number, because 3821921 - 2¹⁴ = 3805537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3821929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2075 + ... + 3456.

It is an arithmetic number, because the mean of its divisors is an integer number (957036).

Almost surely, 2^3821921 is an apocalyptic number.

It is an amenable number.

3821921 is a deficient number, since it is larger than the sum of its proper divisors (6223).

3821921 is an equidigital number, since it uses as much as digits as its factorization.

3821921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6222.

The product of its digits is 864, while the sum is 26.

The square root of 3821921 is about 1954.9734013536. The cubic root of 3821921 is about 156.3485658628.

The spelling of 3821921 in words is "three million, eight hundred twenty-one thousand, nine hundred twenty-one".