21033320321 has 16 divisors (see below), whose sum is σ = 23848608000. Its totient is φ = 18389524608.

The previous prime is 21033320317. The next prime is 21033320327. The reversal of 21033320321 is 12302333012.

It is not a de Polignac number, because 21033320321 - 2² = 21033320317 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21033320293 and 21033320302.

It is not an unprimeable number, because it can be changed into a prime (21033320327) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2267525 + ... + 2276781.

It is an arithmetic number, because the mean of its divisors is an integer number (1490538000).

Almost surely, 2^21033320321 is an apocalyptic number.

It is an amenable number.

21033320321 is a deficient number, since it is larger than the sum of its proper divisors (2815287679).

21033320321 is a wasteful number, since it uses less digits than its factorization.

21033320321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18488.

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 21033320321 its reverse (12302333012), we get a palindrome (33335653333).

The spelling of 21033320321 in words is "twenty-one billion, thirty-three million, three hundred twenty thousand, three hundred twenty-one".