21321021321 has 48 divisors (see below), whose sum is σ = 32772609792. Its totient is φ = 13329360000.

The previous prime is 21321021317. The next prime is 21321021343. The reversal of 21321021321 is 12312012312.

21321021321 is a `hidden beast` number, since 2 + 1 + 321 + 0 + 21 + 321 = 666.

It is not a de Polignac number, because 21321021321 - 2² = 21321021317 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21321021294 and 21321021303.

It is not an unprimeable number, because it can be changed into a prime (21321021521) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2148471 + ... + 2158371.

It is an arithmetic number, because the mean of its divisors is an integer number (682762704).

Almost surely, 2^21321021321 is an apocalyptic number.

It is an amenable number.

21321021321 is a deficient number, since it is larger than the sum of its proper divisors (11451588471).

21321021321 is a wasteful number, since it uses less digits than its factorization.

21321021321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10134 (or 10131 counting only the distinct ones).

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

Adding to 21321021321 its reverse (12312012312), we get a palindrome (33633033633).

Subtracting from 21321021321 its reverse (12312012312), we obtain a palindrome (9009009009).

The spelling of 21321021321 in words is "twenty-one billion, three hundred twenty-one million, twenty-one thousand, three hundred twenty-one".