4021221 has 4 divisors (see below), whose sum is σ = 5361632. Its totient is φ = 2680812.

The previous prime is 4021211. The next prime is 4021229. The reversal of 4021221 is 1221204.

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 not a de Polignac number, because 4021221 - 2⁵ = 4021189 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 4021197 and 4021206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4021229) 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, 670201 + ... + 670206.

It is an arithmetic number, because the mean of its divisors is an integer number (1340408).

Almost surely, 2^4021221 is an apocalyptic number.

It is an amenable number.

4021221 is a deficient number, since it is larger than the sum of its proper divisors (1340411).

4021221 is a wasteful number, since it uses less digits than its factorization.

4021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1340410.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 4021221 is about 2005.2982321839. The cubic root of 4021221 is about 159.0203288750.

Adding to 4021221 its reverse (1221204), we get a palindrome (5242425).

The spelling of 4021221 in words is "four million, twenty-one thousand, two hundred twenty-one".