21220020221 has 8 divisors (see below), whose sum is σ = 21356848800. Its totient is φ = 21083395120.

The previous prime is 21220020187. The next prime is 21220020223. The reversal of 21220020221 is 12202002212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220020221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220020196 and 21220020205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220020223) 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, 161210 + ... + 261588.

It is an arithmetic number, because the mean of its divisors is an integer number (2669606100).

Almost surely, 2^21220020221 is an apocalyptic number.

It is an amenable number.

21220020221 is a deficient number, since it is larger than the sum of its proper divisors (136828579).

21220020221 is a wasteful number, since it uses less digits than its factorization.

21220020221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101739.

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21220020221 its reverse (12202002212), we get a palindrome (33422022433).

The spelling of 21220020221 in words is "twenty-one billion, two hundred twenty million, twenty thousand, two hundred twenty-one".