21022000221 has 4 divisors (see below), whose sum is σ = 28029333632. Its totient is φ = 14014666812.

The previous prime is 21022000171. The next prime is 21022000249. The reversal of 21022000221 is 12200022012.

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 not a de Polignac number, because 21022000221 - 2¹⁴ = 21021983837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21022000197 and 21022000206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022000291) 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, 3503666701 + ... + 3503666706.

It is an arithmetic number, because the mean of its divisors is an integer number (7007333408).

Almost surely, 2^21022000221 is an apocalyptic number.

It is an amenable number.

21022000221 is a deficient number, since it is larger than the sum of its proper divisors (7007333411).

21022000221 is an equidigital number, since it uses as much as digits as its factorization.

21022000221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7007333410.

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 21022000221 its reverse (12200022012), we get a palindrome (33222022233).

The spelling of 21022000221 in words is "twenty-one billion, twenty-two million, two hundred twenty-one", and thus it is an aban number.