21003022221 has 4 divisors (see below), whose sum is σ = 28004029632. Its totient is φ = 14002014812.

The previous prime is 21003022219. The next prime is 21003022231. The reversal of 21003022221 is 12222030012.

It is a happy number.

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 21003022221 - 2¹ = 21003022219 is a prime.

It is a super-2 number, since 2×21003022221² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21003022221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003022231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3500503701 + ... + 3500503706.

It is an arithmetic number, because the mean of its divisors is an integer number (7001007408).

Almost surely, 2^21003022221 is an apocalyptic number.

It is an amenable number.

21003022221 is a deficient number, since it is larger than the sum of its proper divisors (7001007411).

21003022221 is an equidigital number, since it uses as much as digits as its factorization.

21003022221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7001007410.

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21003022221 its reverse (12222030012), we get a palindrome (33225052233).

The spelling of 21003022221 in words is "twenty-one billion, three million, twenty-two thousand, two hundred twenty-one".