21000213321 has 32 divisors (see below), whose sum is σ = 29442096000. Its totient is φ = 13300392960.

The previous prime is 21000213313. The next prime is 21000213389. The reversal of 21000213321 is 12331200012.

It is not a de Polignac number, because 21000213321 - 2³ = 21000213313 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21000213321.

It is not an unprimeable number, because it can be changed into a prime (21000213821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 965041 + ... + 986561.

It is an arithmetic number, because the mean of its divisors is an integer number (920065500).

Almost surely, 2^21000213321 is an apocalyptic number.

It is an amenable number.

21000213321 is a deficient number, since it is larger than the sum of its proper divisors (8441882679).

21000213321 is a wasteful number, since it uses less digits than its factorization.

21000213321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21769.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21000213321 its reverse (12331200012), we get a palindrome (33331413333).

The spelling of 21000213321 in words is "twenty-one billion, two hundred thirteen thousand, three hundred twenty-one".