21220003213 has 4 divisors (see below), whose sum is σ = 21238799740. Its totient is φ = 21201206688.

The previous prime is 21220003171. The next prime is 21220003219. The reversal of 21220003213 is 31230002212.

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 4791685284 + 16428317929 = 69222^2 + 128173^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220003213 - 2¹³ = 21219995021 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 (21220003219) 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, 9396570 + ... + 9398827.

It is an arithmetic number, because the mean of its divisors is an integer number (5309699935).

Almost surely, 2^21220003213 is an apocalyptic number.

It is an amenable number.

21220003213 is a deficient number, since it is larger than the sum of its proper divisors (18796527).

21220003213 is a wasteful number, since it uses less digits than its factorization.

21220003213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18796526.

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 21220003213 its reverse (31230002212), we get a palindrome (52450005425).

The spelling of 21220003213 in words is "twenty-one billion, two hundred twenty million, three thousand, two hundred thirteen".