21321130221 has 24 divisors (see below), whose sum is σ = 31595281536. Its totient is φ = 13850429760.

The previous prime is 21321130217. The next prime is 21321130241. The reversal of 21321130221 is 12203112312.

21321130221 is a `hidden beast` number, since 21 + 321 + 1 + 302 + 21 = 666.

It is not a de Polignac number, because 21321130221 - 2² = 21321130217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21321130194 and 21321130203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321130241) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 140965 + ... + 250026.

It is an arithmetic number, because the mean of its divisors is an integer number (1316470064).

Almost surely, 2^21321130221 is an apocalyptic number.

It is an amenable number.

21321130221 is a deficient number, since it is larger than the sum of its proper divisors (10274151315).

21321130221 is a wasteful number, since it uses less digits than its factorization.

21321130221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391153 (or 391150 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21321130221 its reverse (12203112312), we get a palindrome (33524242533).

The spelling of 21321130221 in words is "twenty-one billion, three hundred twenty-one million, one hundred thirty thousand, two hundred twenty-one".