21000222321 has 72 divisors (see below), whose sum is σ = 32367565440. Its totient is φ = 12037491648.

The previous prime is 21000222311. The next prime is 21000222343. The reversal of 21000222321 is 12322200012.

It is a happy number.

It is not a de Polignac number, because 21000222321 - 2¹³ = 21000214129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21000222321.

It is not an unprimeable number, because it can be changed into a prime (21000222311) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 87866920 + ... + 87867158.

It is an arithmetic number, because the mean of its divisors is an integer number (449549520).

Almost surely, 2^21000222321 is an apocalyptic number.

It is an amenable number.

21000222321 is a deficient number, since it is larger than the sum of its proper divisors (11367343119).

21000222321 is a wasteful number, since it uses less digits than its factorization.

21000222321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451 (or 353 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21000222321 its reverse (12322200012), we get a palindrome (33322422333).

The spelling of 21000222321 in words is "twenty-one billion, two hundred twenty-two thousand, three hundred twenty-one".