4021331221 has 2 divisors, whose sum is σ = 4021331222. Its totient is φ = 4021331220.

The previous prime is 4021331219. The next prime is 4021331239. The reversal of 4021331221 is 1221331204.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4015756900 + 5574321 = 63370^2 + 2361^2 .

It is a cyclic number.

It is not a de Polignac number, because 4021331221 - 2¹ = 4021331219 is a prime.

It is a super-2 number, since 2×4021331221² = 32342209577978701682, which contains 22 as substring.

Together with 4021331219, 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 (4021332221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2010665610 + 2010665611.

It is an arithmetic number, because the mean of its divisors is an integer number (2010665611).

Almost surely, 2^4021331221 is an apocalyptic number.

It is an amenable number.

4021331221 is a deficient number, since it is larger than the sum of its proper divisors (1).

4021331221 is an equidigital number, since it uses as much as digits as its factorization.

4021331221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 4021331221 is about 63413.9670813930. The cubic root of 4021331221 is about 1590.2178176864.

Adding to 4021331221 its reverse (1221331204), we get a palindrome (5242662425).

The spelling of 4021331221 in words is "four billion, twenty-one million, three hundred thirty-one thousand, two hundred twenty-one".