3918221 has 4 divisors (see below), whose sum is σ = 3927744. Its totient is φ = 3908700.

The previous prime is 3918209. The next prime is 3918251. The reversal of 3918221 is 1228193.

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 3918221 - 2⁶ = 3918157 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3918251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4115 + ... + 4976.

It is an arithmetic number, because the mean of its divisors is an integer number (981936).

Almost surely, 2^3918221 is an apocalyptic number.

It is an amenable number.

3918221 is a deficient number, since it is larger than the sum of its proper divisors (9523).

3918221 is an equidigital number, since it uses as much as digits as its factorization.

3918221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9522.

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

The square root of 3918221 is about 1979.4496709944. The cubic root of 3918221 is about 157.6508473317.

The spelling of 3918221 in words is "three million, nine hundred eighteen thousand, two hundred twenty-one".