21021310321 has 8 divisors (see below), whose sum is σ = 22934023488. Its totient is φ = 19108878000.

The previous prime is 21021310319. The next prime is 21021310333. The reversal of 21021310321 is 12301312012.

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 21021310321 - 2¹ = 21021310319 is a prime.

It is a super-2 number, since 2×21021310321² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21021310295 and 21021310304.

It is not an unprimeable number, because it can be changed into a prime (21021310361) 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, 105411 + ... + 230551.

It is an arithmetic number, because the mean of its divisors is an integer number (2866752936).

Almost surely, 2^21021310321 is an apocalyptic number.

It is an amenable number.

21021310321 is a deficient number, since it is larger than the sum of its proper divisors (1912713167).

21021310321 is a wasteful number, since it uses less digits than its factorization.

21021310321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140423.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21021310321 its reverse (12301312012), we get a palindrome (33322622333).

The spelling of 21021310321 in words is "twenty-one billion, twenty-one million, three hundred ten thousand, three hundred twenty-one".