21021220331321 has 8 divisors (see below), whose sum is σ = 24328356261120. Its totient is φ = 17790110515008.

The previous prime is 21021220331219. The next prime is 21021220331381. The reversal of 21021220331321 is 12313302212012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021220331321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021220331381) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19006527776 + ... + 19006528881.

It is an arithmetic number, because the mean of its divisors is an integer number (3041044532640).

Almost surely, 2^{21021220331321} is an apocalyptic number.

It is an amenable number.

21021220331321 is a deficient number, since it is larger than the sum of its proper divisors (3307135929799).

21021220331321 is an equidigital number, since it uses as much as digits as its factorization.

21021220331321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38013056743.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 21021220331321 its reverse (12313302212012), we get a palindrome (33334522543333).

The spelling of 21021220331321 in words is "twenty-one trillion, twenty-one billion, two hundred twenty million, three hundred thirty-one thousand, three hundred twenty-one".