21221322013 has 4 divisors (see below), whose sum is σ = 21338567068. Its totient is φ = 21104076960.

The previous prime is 21221322011. The next prime is 21221322019. The reversal of 21221322013 is 31022312212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 594043129 + 20627278884 = 24373^2 + 143622^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221322013 - 2¹ = 21221322011 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221322011) 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 3 ways as a sum of consecutive naturals, for example, 58622256 + ... + 58622617.

It is an arithmetic number, because the mean of its divisors is an integer number (5334641767).

Almost surely, 2^21221322013 is an apocalyptic number.

It is an amenable number.

21221322013 is a deficient number, since it is larger than the sum of its proper divisors (117245055).

21221322013 is a wasteful number, since it uses less digits than its factorization.

21221322013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117245054.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21221322013 its reverse (31022312212), we get a palindrome (52243634225).

The spelling of 21221322013 in words is "twenty-one billion, two hundred twenty-one million, three hundred twenty-two thousand, thirteen".