21220222021 has 8 divisors (see below), whose sum is σ = 21924391424. Its totient is φ = 20517280560.

The previous prime is 21220221983. The next prime is 21220222033. The reversal of 21220222021 is 12022202212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21220222021 - 2⁹ = 21220221509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220221986 and 21220222004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220222921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 271785 + ... + 341038.

It is an arithmetic number, because the mean of its divisors is an integer number (2740548928).

Almost surely, 2^21220222021 is an apocalyptic number.

It is an amenable number.

21220222021 is a deficient number, since it is larger than the sum of its proper divisors (704169403).

21220222021 is a wasteful number, since it uses less digits than its factorization.

21220222021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613971.

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21220222021 its reverse (12022202212), we get a palindrome (33242424233).

The spelling of 21220222021 in words is "twenty-one billion, two hundred twenty million, two hundred twenty-two thousand, twenty-one".