21068509221 has 24 divisors (see below), whose sum is σ = 30609206784. Its totient is φ = 13964106240.

The previous prime is 21068509219. The next prime is 21068509229. The reversal of 21068509221 is 12290586012.

It is not a de Polignac number, because 21068509221 - 2¹ = 21068509219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21068509229) 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 23 ways as a sum of consecutive naturals, for example, 5390550 + ... + 5394456.

It is an arithmetic number, because the mean of its divisors is an integer number (1275383616).

Almost surely, 2^21068509221 is an apocalyptic number.

It is an amenable number.

21068509221 is a deficient number, since it is larger than the sum of its proper divisors (9540697563).

21068509221 is a wasteful number, since it uses less digits than its factorization.

21068509221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7241 (or 7238 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 21068509221 in words is "twenty-one billion, sixty-eight million, five hundred nine thousand, two hundred twenty-one".