21221301321 has 16 divisors (see below), whose sum is σ = 34297053120. Its totient is φ = 12861394560.

The previous prime is 21221301301. The next prime is 21221301341. The reversal of 21221301321 is 12310312212.

21221301321 is a `hidden beast` number, since 21 + 2 + 21 + 301 + 321 = 666.

It is an interprime number because it is at equal distance from previous prime (21221301301) and next prime (21221301341).

It is not a de Polignac number, because 21221301321 - 2¹⁰ = 21221300297 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21221301294 and 21221301303.

It is not an unprimeable number, because it can be changed into a prime (21221301301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35725800 + ... + 35726393.

It is an arithmetic number, because the mean of its divisors is an integer number (2143565820).

Almost surely, 2^21221301321 is an apocalyptic number.

It is an amenable number.

21221301321 is a deficient number, since it is larger than the sum of its proper divisors (13075751799).

21221301321 is a wasteful number, since it uses less digits than its factorization.

21221301321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71452213 (or 71452207 counting only the distinct ones).

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

Adding to 21221301321 its reverse (12310312212), we get a palindrome (33531613533).

The spelling of 21221301321 in words is "twenty-one billion, two hundred twenty-one million, three hundred one thousand, three hundred twenty-one".