21011330321 has 8 divisors (see below), whose sum is σ = 21156846240. Its totient is φ = 20866017312.

The previous prime is 21011330317. The next prime is 21011330359. The reversal of 21011330321 is 12303311012.

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

It is a cyclic number.

It is not a de Polignac number, because 21011330321 - 2² = 21011330317 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21011330321.

It is not an unprimeable number, because it can be changed into a prime (21011330371) 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, 160106 + ... + 260108.

It is an arithmetic number, because the mean of its divisors is an integer number (2644605780).

Almost surely, 2^21011330321 is an apocalyptic number.

It is an amenable number.

21011330321 is a deficient number, since it is larger than the sum of its proper divisors (145515919).

21011330321 is a wasteful number, since it uses less digits than its factorization.

21011330321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101455.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21011330321 its reverse (12303311012), we get a palindrome (33314641333).

The spelling of 21011330321 in words is "twenty-one billion, eleven million, three hundred thirty thousand, three hundred twenty-one".