3821221 has 2 divisors, whose sum is σ = 3821222. Its totient is φ = 3821220.

The previous prime is 3821219. The next prime is 3821231. The reversal of 3821221 is 1221283.

3821221 is nontrivially palindromic in base 12.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2102500 + 1718721 = 1450^2 + 1311^2 .

It is a cyclic number.

It is not a de Polignac number, because 3821221 - 2¹ = 3821219 is a prime.

Together with 3821219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3821231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1910610 + 1910611.

It is an arithmetic number, because the mean of its divisors is an integer number (1910611).

Almost surely, 2^3821221 is an apocalyptic number.

It is an amenable number.

3821221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3821221 is an equidigital number, since it uses as much as digits as its factorization.

3821221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192, while the sum is 19.

The square root of 3821221 is about 1954.7943625865. The cubic root of 3821221 is about 156.3390199932.

The spelling of 3821221 in words is "three million, eight hundred twenty-one thousand, two hundred twenty-one".