21004305321 has 8 divisors (see below), whose sum is σ = 28012745664. Its totient is φ = 13999367600.

The previous prime is 21004305293. The next prime is 21004305323. The reversal of 21004305321 is 12350340012.

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 21004305321 - 2¹⁴ = 21004288937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21004305323) 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, 861630 + ... + 885671.

It is an arithmetic number, because the mean of its divisors is an integer number (3501593208).

Almost surely, 2^21004305321 is an apocalyptic number.

It is an amenable number.

21004305321 is a deficient number, since it is larger than the sum of its proper divisors (7008440343).

21004305321 is a wasteful number, since it uses less digits than its factorization.

21004305321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1751311.

The product of its (nonzero) digits is 720, while the sum is 21.

Adding to 21004305321 its reverse (12350340012), we get a palindrome (33354645333).

The spelling of 21004305321 in words is "twenty-one billion, four million, three hundred five thousand, three hundred twenty-one".