21003323220221 has 4 divisors (see below), whose sum is σ = 21680849775744. Its totient is φ = 20325796664700.

The previous prime is 21003323220203. The next prime is 21003323220233. The reversal of 21003323220221 is 12202232330012.

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 21003323220221 - 2⁴² = 16605276709117 is a prime.

It is a super-2 number, since 2×21003323220221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003323220251) 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, 338763277715 + ... + 338763277776.

It is an arithmetic number, because the mean of its divisors is an integer number (5420212443936).

Almost surely, 2^{21003323220221} is an apocalyptic number.

It is an amenable number.

21003323220221 is a deficient number, since it is larger than the sum of its proper divisors (677526555523).

21003323220221 is an equidigital number, since it uses as much as digits as its factorization.

21003323220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677526555522.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21003323220221 its reverse (12202232330012), we get a palindrome (33205555550233).

The spelling of 21003323220221 in words is "twenty-one trillion, three billion, three hundred twenty-three million, two hundred twenty thousand, two hundred twenty-one".