4001421221 has 16 divisors (see below), whose sum is σ = 4631385600. Its totient is φ = 3386156928.

The previous prime is 4001421211. The next prime is 4001421233. The reversal of 4001421221 is 1221241004.

It is not a de Polignac number, because 4001421221 - 2¹⁴ = 4001404837 is a prime.

It is a super-2 number, since 2×4001421221² = 32022743575738261682, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 4001421221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4001421211) 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 in 15 ways as a sum of consecutive naturals, for example, 443471 + ... + 452403.

It is an arithmetic number, because the mean of its divisors is an integer number (289461600).

Almost surely, 2^4001421221 is an apocalyptic number.

It is an amenable number.

4001421221 is a deficient number, since it is larger than the sum of its proper divisors (629964379).

4001421221 is an equidigital number, since it uses as much as digits as its factorization.

4001421221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9748.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 4001421221 is about 63256.7879440618. The cubic root of 4001421221 is about 1587.5890336822.

Adding to 4001421221 its reverse (1221241004), we get a palindrome (5222662225).

The spelling of 4001421221 in words is "four billion, one million, four hundred twenty-one thousand, two hundred twenty-one".