21123332321 has 16 divisors (see below), whose sum is σ = 26024135424. Its totient is φ = 16696131264.

The previous prime is 21123332317. The next prime is 21123332369. The reversal of 21123332321 is 12323332112.

It is a cyclic number.

It is not a de Polignac number, because 21123332321 - 2² = 21123332317 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21123332311) 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, 25685 + ... + 207138.

It is an arithmetic number, because the mean of its divisors is an integer number (1626508464).

Almost surely, 2^21123332321 is an apocalyptic number.

It is an amenable number.

21123332321 is a deficient number, since it is larger than the sum of its proper divisors (4900803103).

21123332321 is a wasteful number, since it uses less digits than its factorization.

21123332321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233840.

The product of its digits is 1296, while the sum is 23.

Adding to 21123332321 its reverse (12323332112), we get a palindrome (33446664433).

The spelling of 21123332321 in words is "twenty-one billion, one hundred twenty-three million, three hundred thirty-two thousand, three hundred twenty-one".