21220355320 has 16 divisors (see below), whose sum is σ = 47745799560. Its totient is φ = 8488142112.

The previous prime is 21220355293. The next prime is 21220355357. The reversal of 21220355320 is 2355302212.

It is a congruent 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, 265254402 + ... + 265254481.

Almost surely, 2^21220355320 is an apocalyptic number.

21220355320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21220355320 is an abundant number, since it is smaller than the sum of its proper divisors (26525444240).

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

21220355320 is a wasteful number, since it uses less digits than its factorization.

21220355320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530508894 (or 530508890 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 25.

Adding to 21220355320 its reverse (2355302212), we get a palindrome (23575657532).

The spelling of 21220355320 in words is "twenty-one billion, two hundred twenty million, three hundred fifty-five thousand, three hundred twenty".