21211033221 has 64 divisors (see below), whose sum is σ = 36728832000. Its totient is φ = 12093130224.

The previous prime is 21211033219. The next prime is 21211033223. The reversal of 21211033221 is 12233011212.

It is an interprime number because it is at equal distance from previous prime (21211033219) and next prime (21211033223).

It is not a de Polignac number, because 21211033221 - 2¹ = 21211033219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21211033194 and 21211033203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211033223) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4507756 + ... + 4512458.

It is an arithmetic number, because the mean of its divisors is an integer number (573888000).

Almost surely, 2^21211033221 is an apocalyptic number.

21211033221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21211033221 is a deficient number, since it is larger than the sum of its proper divisors (15517798779).

21211033221 is an equidigital number, since it uses as much as digits as its factorization.

21211033221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5220 (or 5200 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21211033221 its reverse (12233011212), we get a palindrome (33444044433).

The spelling of 21211033221 in words is "twenty-one billion, two hundred eleven million, thirty-three thousand, two hundred twenty-one".