21123203303321 has 4 divisors (see below), whose sum is σ = 24140803775232. Its totient is φ = 18105602831412.

The previous prime is 21123203303317. The next prime is 21123203303347. The reversal of 21123203303321 is 12330330232112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21123203303321 - 2² = 21123203303317 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21123203303381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1508800235945 + ... + 1508800235958.

It is an arithmetic number, because the mean of its divisors is an integer number (6035200943808).

Almost surely, 2^{21123203303321} is an apocalyptic number.

It is an amenable number.

21123203303321 is a deficient number, since it is larger than the sum of its proper divisors (3017600471911).

21123203303321 is an equidigital number, since it uses as much as digits as its factorization.

21123203303321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3017600471910.

The product of its (nonzero) digits is 3888, while the sum is 26.

Adding to 21123203303321 its reverse (12330330232112), we get a palindrome (33453533535433).

The spelling of 21123203303321 in words is "twenty-one trillion, one hundred twenty-three billion, two hundred three million, three hundred three thousand, three hundred twenty-one".