21120320221 has 36 divisors (see below), whose sum is σ = 28729366176. Its totient is φ = 15191336160.

The previous prime is 21120320213. The next prime is 21120320237. The reversal of 21120320221 is 12202302112.

It is a happy number.

It is not a de Polignac number, because 21120320221 - 2³ = 21120320213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21120320195 and 21120320204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120320261) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 69370 + ... + 216916.

Almost surely, 2^21120320221 is an apocalyptic number.

It is an amenable number.

21120320221 is a deficient number, since it is larger than the sum of its proper divisors (7609045955).

21120320221 is a wasteful number, since it uses less digits than its factorization.

21120320221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147602 (or 147578 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21120320221 its reverse (12202302112), we get a palindrome (33322622333).

The spelling of 21120320221 in words is "twenty-one billion, one hundred twenty million, three hundred twenty thousand, two hundred twenty-one".