21012003321 has 8 divisors (see below), whose sum is σ = 28016676960.
Its totient is φ = 14007665952.
The previous prime is 21012003283. The next prime is 21012003323. The reversal of 21012003321 is 12330021012.
Adding to 21012003321 its reverse (12330021012), we get a palindrome (33342024333).
It is a sphenic number, since it is the product of 3 distinct primes.
It is not a de Polignac number, because 21012003321 - 211 = 21012001273 is a prime.
It is a Curzon number.
It is a self number, because there is not a number n which added to its sum of digits gives 21012003321.
It is not an unprimeable number, because it can be changed into a prime (21012003323) 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, 182365 + ... + 274373.
It is an arithmetic number, because the mean of its divisors is an integer number (3502084620).
Almost surely, 221012003321 is an apocalyptic number.
It is an amenable number.
21012003321 is a deficient number, since it is larger than the sum of its proper divisors (7004673639).
21012003321 is an equidigital number, since it uses as much as digits as its factorization.
21012003321 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 168135.
The product of its (nonzero) digits is 72, while the sum is 15.
The spelling of 21012003321 in words is "twenty-one billion, twelve million, three thousand, three hundred twenty-one".