21323421064 has 16 divisors (see below), whose sum is σ = 43616088720. Its totient is φ = 9692464080.

The previous prime is 21323421043. The next prime is 21323421121. The reversal of 21323421064 is 46012432312.

It is a happy number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 121155714 + ... + 121155889.

It is an arithmetic number, because the mean of its divisors is an integer number (2726005545).

Almost surely, 2^21323421064 is an apocalyptic number.

It is an amenable number.

21323421064 is an abundant number, since it is smaller than the sum of its proper divisors (22292667656).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21323421064 is a wasteful number, since it uses less digits than its factorization.

21323421064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242311620 (or 242311616 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

Adding to 21323421064 its reverse (46012432312), we get a palindrome (67335853376).

The spelling of 21323421064 in words is "twenty-one billion, three hundred twenty-three million, four hundred twenty-one thousand, sixty-four".